Maya MappingUVs

Mapping UVs

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Contents

Chapter 1 UV mapping overview . . . . . . . . . . . . . . . . . . . . . . . 1Introduction to UV mapping . . . . . . . . . . . . . . . . . . . . . . . . 1Creating UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Viewing and evaluating UVs . . . . . . . . . . . . . . . . . . . . . . . . 4UV mapping tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6UV Texture Editor overview . . . . . . . . . . . . . . . . . . . . . . . . 8UV sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Chapter 2 Mapping UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Planar UV mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Cylindrical UV mapping . . . . . . . . . . . . . . . . . . . . . . . . . 19Spherical UV mapping . . . . . . . . . . . . . . . . . . . . . . . . . . 21Automatic UV mapping . . . . . . . . . . . . . . . . . . . . . . . . . . 22User-defined UV mapping . . . . . . . . . . . . . . . . . . . . . . . . 25Confirm UV placement . . . . . . . . . . . . . . . . . . . . . . . . . . 28Transfer UVs between meshes . . . . . . . . . . . . . . . . . . . . . . . 29

Chapter 3 Editing UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Display UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Select UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Display a subset of UVs . . . . . . . . . . . . . . . . . . . . . . . . . . 33Move, rotate, and scale UVs . . . . . . . . . . . . . . . . . . . . . . . . 35Dolly or track within the UV Texture Editor . . . . . . . . . . . . . . . 41

v

Display a texture behind the UVs . . . . . . . . . . . . . . . . . . . . . 42Delete UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Update a texture image after UV modification . . . . . . . . . . . . . . 45Use the UV Texture Editor grid . . . . . . . . . . . . . . . . . . . . . . 47Save an image of the UV layout . . . . . . . . . . . . . . . . . . . . . . 48Modify UVs using the UV Lattice Tool . . . . . . . . . . . . . . . . . . 49Modify UVs using the UV Smudge Tool . . . . . . . . . . . . . . . . . 51Separate and attach UV shells . . . . . . . . . . . . . . . . . . . . . . . 52Display overlapping UVs . . . . . . . . . . . . . . . . . . . . . . . . . 54Display UV winding order . . . . . . . . . . . . . . . . . . . . . . . . 55Layout UV shells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58Map border UVs to a square or circle . . . . . . . . . . . . . . . . . . . 60Straighten border UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . 62Relax and untangle UVs . . . . . . . . . . . . . . . . . . . . . . . . . . 63Unfold a UV mesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65Example: Lay out a UV shell using unfold and relax . . . . . . . . . . . 73Flip or rotate UV shells . . . . . . . . . . . . . . . . . . . . . . . . . . 79Copy UVs and color attributes between polygons . . . . . . . . . . . . 80

Chapter 4 UV sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83Create UV sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83Switch between UV sets . . . . . . . . . . . . . . . . . . . . . . . . . . 84Duplicate, rename, or delete a UV set . . . . . . . . . . . . . . . . . . . 84Assign a texture to a UV set . . . . . . . . . . . . . . . . . . . . . . . . 85Copy UVs from one UV set to another . . . . . . . . . . . . . . . . . . 86Working with per-instance UV sets . . . . . . . . . . . . . . . . . . . . 87Edit NURBS UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Chapter 5 UVs menu reference . . . . . . . . . . . . . . . . . . . . . . . . 97Create UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Create UVs > Planar Mapping . . . . . . . . . . . . . . . . . . . . 97Create UVs > Cylindrical Mapping . . . . . . . . . . . . . . . . . 99Create UVs > Spherical Mapping . . . . . . . . . . . . . . . . . 100Create UVs > Automatic Mapping . . . . . . . . . . . . . . . . . 102Create UVs > Create UVs Based On Camera . . . . . . . . . . . . 106Create UVs > Best Plane Texturing Tool . . . . . . . . . . . . . . 107Create UVs > Assign Shader to Each Projection . . . . . . . . . . 107Create UVs > Create Empty UV Set . . . . . . . . . . . . . . . . 107Create UVs > Copy UVs to UV Set . . . . . . . . . . . . . . . . . 108Create UVs > Set Current UV Set . . . . . . . . . . . . . . . . . 108Create UVs > Rename Current UV Set . . . . . . . . . . . . . . . 109Create UVs > Delete Current UV Set . . . . . . . . . . . . . . . . 109Create UVs > UV Set Editor . . . . . . . . . . . . . . . . . . . . 109Create UVs > Per Instance Sharing . . . . . . . . . . . . . . . . 109

Edit UVs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

vi | Contents

Edit UVs > Normalize . . . . . . . . . . . . . . . . . . . . . . . 110Edit UVs > Unitize . . . . . . . . . . . . . . . . . . . . . . . . . 111Edit UVs > Flip . . . . . . . . . . . . . . . . . . . . . . . . . . . 111Edit UVs > Rotate . . . . . . . . . . . . . . . . . . . . . . . . . 113Edit UVs > Grid . . . . . . . . . . . . . . . . . . . . . . . . . . 114Edit UVs > Align . . . . . . . . . . . . . . . . . . . . . . . . . . 114Edit UVs > Warp Image . . . . . . . . . . . . . . . . . . . . . . 115Edit UVs > Map UV Border . . . . . . . . . . . . . . . . . . . . 117Edit UVs > Straighten UV Border . . . . . . . . . . . . . . . . . 120Edit UVs > Relax . . . . . . . . . . . . . . . . . . . . . . . . . . 121Edit UVs > Unfold . . . . . . . . . . . . . . . . . . . . . . . . . 123Edit UVs > Layout . . . . . . . . . . . . . . . . . . . . . . . . . 129Edit UVs > Cut UV Edges . . . . . . . . . . . . . . . . . . . . . 134Edit UVs > Split UVs . . . . . . . . . . . . . . . . . . . . . . . . 135Edit UVs > Sew UV Edges . . . . . . . . . . . . . . . . . . . . . 135Edit UVs > Move and Sew UV Edges . . . . . . . . . . . . . . . . 135Edit UVs > Merge UVs . . . . . . . . . . . . . . . . . . . . . . . 136Edit UVs > Delete UVs . . . . . . . . . . . . . . . . . . . . . . . 137Edit UVs > UV Texture Editor . . . . . . . . . . . . . . . . . . . 137

Chapter 6 UVs windows and editors reference . . . . . . . . . . . . . . . 139UV Texture Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

UV Texture Editor reference . . . . . . . . . . . . . . . . . . . . 139UV Texture Editor menu bar . . . . . . . . . . . . . . . . . . . . 140UV Texture Editor toolbar . . . . . . . . . . . . . . . . . . . . . 154

UV Set Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

Chapter 7 UVs tool reference . . . . . . . . . . . . . . . . . . . . . . . . 163Move tool (in UV texture editor) . . . . . . . . . . . . . . . . . . . . 163

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

Contents | vii

viii

UV mapping overview

Introduction to UV mappingUVs (pronounced U-VEEZ) are two-dimensional texture coordinates that residewith the vertex component information for polygonal and subdivision surfacemeshes. UVs exist to define a two-dimensional texture coordinate system, calledUV texture space. UV texture space uses the letters U and V to indicate the axesin 2D. UV texture space facilitates the placement of image texture maps on a3D surface.

UVs are essential in that they provide the connection between the surface meshand how the image texture gets mapped onto the surface mesh. That is, UVsact as marker points that control which points (pixels) on the texture mapcorrespond to which points (vertices) on the mesh. Textures applied to polygonor subdivision surfaces that do not possess UV texture coordinates will notrender.

Although Maya creates UVs by default for many primitive types, you’ll need torearrange the UVs in most cases, because the default arrangement will usuallynot match any subsequent edits to the model you may make. In addition, thelocation of the UV texture coordinates do not automatically update when youedit a surface mesh.

In most cases, you map and arrange UVs after you have completed your modelingand before you assign textures to the model. Otherwise, changing the modelwill create a mismatch between the model and the UVs, and affect how anytextures appear on the model.

Understanding the concept of UVs and how to map them to a surface, andsubsequently lay them out accurately is essential for producing textures onpolygonal and subdivision surfaces when working in Maya. Understanding how

1

1

UVs work is also important when you need to paint textures, fur, or hair ontoa 3D model.

UVs and texture mapping

Texture mapping polygon and subdivision surfaces in Maya differs from howyou texture NURBS surfaces.

For NURBS surface types, each surface mesh is defined as a four-sided squareor rectangular patch that has specific U and V directions. For NURBS surfacetypes the texture coordinates (UVs) that control the placement of a textureexist by default and are implicitly connected to the control vertices. Whenthe control vertices get repositioned, so do the positions of the correspondingUV texture coordinates. Any textures mapped to the surface are also affectedas a result. That is, moving a CV will affect how the texture map appears onthe NURBS surface.

For polygon and subdivision surface types, the shape of surface meshes isusually much more irregular compared to NURBS surface types. Texturecoordinates (UVs) associated with these surface types do not always exist bydefault, and so must be explicitly created, and subsequently modified in mostcases, so that the surface mesh can accommodate a texture map.

UV mapping

The process of creating explicit UVs for a surface mesh is called UV mapping.UV mapping is a process whereby you create, edit, and otherwise arrange theUVs (that appear as a flattened, two-dimensional representation of the surfacemesh, over top of the two-dimensional image to be used as a texture as itappears in the UV Texture Editor.

The UV mapping process results in a correlation between the image and howit appears as a texture when mapped onto the three-dimensional surface mesh.UV mapping is a critical skill to master for accurate and realistic textures onpolygonal surfaces.

■ You create UVs by mapping them onto your surface mesh using a varietyof options. For more information see the Related topics section below.

■ You view and edit UVs using the UV Texture Editor. You can display thetexture image as a background image to let you more easily correlate theUVs to the texture. The UV Texture Editor provides many useful tools forlaying out and manipulating the 2D representation of UVs. For moreinformation see UV Texture Editor overview on page 8.

2 | Chapter 1 UV mapping overview

NOTE You only need to be concerned about UV texture coordinates whenyou want to apply a texture map to polygons. UV mapping is not necessaryfor creating and reshaping polygon and subdivision surfaces.

Related topics

■ Creating UVs on page 3

■ Viewing and evaluating UVs on page 4

■ UV Texture Editor overview on page 8

■ UV mapping tips on page 6

Creating UVsIn Maya, UV texture coordinates (UVs) can be created for polygon surfacemeshes using the following UV mapping techniques:

■ Automatic UV mapping on page 22

■ Planar UV mapping on page 15

■ Cylindrical UV mapping on page 19

■ Spherical UV mapping on page 21

■ User-defined UV mapping on page 25

■ Camera UV mapping - see Planar UV mapping on page 15

Each UV mapping technique produces UV texture coordinates for the surfacemesh by projecting them onto the surface mesh based on its inherentprojection method. As a result, the UV texture coordinates have an initial 2Dspatial correlation to the vertex information in the 3D world space coordinatesystem. It is this correlation between the texture map and the surface meshvia the UVs that positions the texture on the surface.

The initial mapping produced via the above UV mapping techniques does notusually produce the final UV arrangement that is required for a texture. As aresult, you will often need to perform further editing operations on the UVsusing the UV Texture Editor.

Creating UVs | 3

The polygon and subdivision surface primitive types in Maya have default UVtexture coordinates that can be used for texture mapping. However, if youmodify the default primitives in any way (that is, scale, extrude faces, insertor delete edges) you will need to map a new set of UV texture coordinatesonto the modified object to suit your texture mapping requirements.

The best workflow is to map UVs onto a model only when the it is complete.

Related topics

■ Introduction to UV mapping on page 1



Viewing and evaluating UVsOnce you have mapped UVs onto a model you view and edit the resultingUV texture coordinates using the UV Texture Editor. The UV Texture Editorlets you view the two-dimensional UV mesh on its own or in relation to theimage texture. The UV Texture Editor lets you manipulate the componentsof the UV mesh in the 2D view much like you work with other polygoncomponents in Maya.

In some instances the default UV projection may not appear in a manner youexpect or require. In these situations you must visually evaluate, then manuallyedit the UV layout to rearrange the position of the UVs within the UV TextureEditor to better suit the requirements of the texture.

In terms of production workflow, you typically map and edit (rearrange) theUVs once you have completed your modeling and before you assign texturesto the model. How you edit the UVs for a particular polygon mesh dependson the texture mapping requirements you have.

The following are some examples of situations where UVs need to be editedto meet specific texturing requirements.

■ When the image for a texture map already exists, the UV mesh (andpossibly the surface mesh) will need to be modified to conform to therequirements of the image. One example of this is when texture mappinga games character and the artwork for the texture maps already exist for aknown film actor, athlete, or comic book character. In addition, the imagefor the character's textures may be comprised of many smaller separate


images for the various components of the character on the same image(For example, sub-images of the face or head, torso, legs etc.). This methodof laying out many images on a single image is commonly referred to asa decal sheet and is very efficient in terms of texture and memory usage foran interactive game application. When using a decal sheet approach theUVs must be arranged so they match up with the corresponding imageson texture map as it appears in the UV Texture Editor.

■ When you want to reference the same image multiple times for a texturemap you will want the UVs to lay directly on top of each other whenviewed in the UV Texture Editor. This approach is useful and efficient insituations when the UVs can share the same region of a texture image. Forexample, if you had a brick texture that you wanted repeated on severalbuildings in a scene you could lay each separate UV mesh in exactly thesame position within the UV Texture Editor. Otherwise overlapping UVsare generally not desirable and will produce unexpected texture mappingresults. When UVs overlap you can lay them out to not overlap using EditUVs > Layout.

■ When you need to manually reassemble a UV mesh after using Automaticmapping to create UVs for a surface mesh. Automatic mapping invariablyproduces multiple projections for a surface mesh based on the shape ofthe surface mesh. As a result, the UV projections appear as many separateUV components in the UV Texture Editor. This can be problematic whenyou need to have a UV mesh that is one contiguous piece to allow a textureartist to paint directly on the 3D object. You can reposition and attach theindividual UV components using features in the UV Texture Editor suchas Polygons > Move and Sew UV Edges.

■ When the shape of the projected UVs are badly distorted compared to the3D surface mesh the resulting texture map will be compressed, stretchedor otherwise distorted on the surface mesh in an undesirable fashion. Thereare many options for correcting these situations using features in the UVTexture Editor such features as Unfold and Relax.

NOTE To create a UV mapping arrangement that works best for your model,you may need to try a variety of mapping techniques, until you find a mappingarrangement that is suitable. For more information on laying out UVs see UVmapping tips on page 6.

Related topics


Viewing and evaluating UVs | 5




UV mapping tipsMaya provides a number of features that let you easily create and edit UVtexture coordinates for texture mapping your polygon and subdivision surfaces.The UV Texture Editor (Edit UVs > UV Texture Editor) is the primary tool forarranging and laying out UVs for optimal textures.

Knowing how to arrange UV texture coordinates is an important skill to masterthat depends on whether you are generating a new texture using the UVs asa guide, or if you are adapting the UVs to optimally fit an existing image. Thebest arrangement depends on the types of textures you will apply and alsoupon whether you are creating rendered images or models for interactivegames. A full description of UV arrangement is out of the scope of this guidebut you should consider the following guidelines:

Keep UVs within the 0 to +1 texture coordinates

The UV Texture Editor displays a grid marking the texture space for UVs. Theworking area of the grid begins at 0 and extends to 1. By default, the UVmapping operations in Maya automatically fit UVs within the 0 to 1coordinates. While it is possible to move or scale the UVs so they reside outsideof this 0 to 1 region, you should keep the UVs for a surface positioned withinthese 0 to 1 coordinates, in the majority of situations.

When the UVs extend beyond the 0 to 1 range, the texture will appear torepeat or wrap around the corresponding vertices when viewed in the 3Dscene or rendered image. The exception to this guideline is when you actuallywant the texture to repeat on the surface, such as a brick texture along themodel of a wall.

Avoid overlapping UV shells

UV points have interconnecting lines that form a shape, called a UV shell. Ifany of the UV shells overlap in the UV Texture Editor, the texture will appearto repeat on the corresponding vertices. In general, you should avoidoverlapping UVs, unless you want the texture to repeat. For example, if youwant the arms of a character to share the same texture pattern, you can place


the UV shell corresponding to one arm on top of the piece corresponding tothe other arm, using the Move UV Shell Tool.

Some UV projection operations often result in overlapping UV shells, but youcan easily separate the shells using the Layout feature, as described in LayoutUV shells on page 58.

Spacing between UV shells

The spacing between UV shells is an important consideration. You’ll want tohave the UV shells as close together as possible to maximize the UV texturespace. However, if the shells are too close together, there is the possibility thatthe textures may bleed between one surface to another.

Snapping UVs

You can use snapping in the UV Texture Editor to lock your transformationsto existing objects in the scene. This functionality is similar to the snappingfunctionality in the scene view.

You can use the Preserve Component Spacing option in the Move Tool settingswhen transforming multiple UVs to maintain their relative spacing.

IconHoldTo snap to...

xGrid intersections

(In the Status Line)

vOther UVs (points)

(In the Status Line)

Pixels

(In the UV Texture Editor toolbar)

UV mapping tips | 7

NOTE

■ If snapping is on and you drag an axis manipulator (as opposed to themanipulator’s center), the manipulator snaps to the nearest point or gridintersection restricted to that axis (depending on the snapping mode).Alternatively, you can use Shift + x or Shift + v to snap to the nearest pointrestricted by the U or V axis respectively.

■ Pixel Snapping is measured by monitor pixels. You can zoom in close tothe UVs to achieve better results. This setting also affects snapping forrotating and scaling pivot locations.

Related topics





UV Texture Editor overviewWindow > UV Texture Editor

Edit UVs > UV Texture Editor

In scene view: Panels > Panel > UV Texture Editor

The UV Texture Editor lets you view and interactively edit the UV texturecoordinates for polygon, NURBS, and subdivision surfaces within a 2D view.

You can select, move, scale, and generally modify the UV topology for a surfacevery much like you work with other modeling tools within Maya. You canalso view the image associated with the assigned texture map as a backdropwithin the UV Texture Editor and modify the UV layout to match as required.


Maya lets you easily compare what you view in the 3D scene view and in theUV Texture Editor’s 2D texture coordinate view by displaying the perspectiveview and the UV Texture Editor simultaneously. For example, you can selecta UV within the 3D scene view and simultaneously see the same selected UVcoordinate in the 2D view of the UV Texture Editor and vice versa. This isuseful when you’re editing UVs and need to understand how an item in the2D view relates to the 3D model in the scene view. For this reason, many Mayausers find it invaluable to have the Maya perspective view and the UV TextureEditor displayed side-by-side when performing UV texture and layout work.You select this layout from the layout shortcuts section of the Toolbox.

UV Texture Editor overview | 9

The UV Texture Editor contains tools that allow you to modify the UV texturecoordinates. For example, you can perform such actions as rotating and flippingUVs as well as cutting and sewing UVs in order to achieve the UV layout yourequire. You can also output a bitmap image of the final UV layout so it canbe used as a background for texture creation work.

There are separate menus for polygons and subdivision surfaces UV tasks.Many of the items within the UV Texture Editor are also accessible from theUV Texture Editor’s toolbar as icons. As well, some of the items that arecontained within the UV Texture Editor are also available in the Edit UVsmenu from the Polygons menu set.

Viewing items in the UV Texture Editor

When viewing UV texture coordinates in the UV Texture Editor you:

■ use the standard camera move keys (Alt + the middle mouse button andAlt + the right mouse button) to track and dolly within the 2D textureview.

■ press f in the UV Texture Editor to frame any selected items in the 2D view.

Marking menus in the UV Texture Editor

UV specific marking menus are available when you work in the UV TextureEditor. This saves you time and streamlines your UV editing workflow. When


you Shift + right-click in the UV Texture Editor the marking menu showsdifferent items depending on what components are currently selected:

■ When UV texture coordinates are currently selected the marking menu showspossible UV modification operations (for example, Relax, Unfold, SmudgeTool, and Lattice Tool are available). While the marking menu is displayed,simply drag your mouse to highlight the desired item in the menu; theitem is selected as if it were selected from the related UV Texture Editorlocation in the menu or toolbar.

■ When a polygon edge is currently selected the marking menu shows possibleUV edge modification operations for the selected component (for example,Cut UV Edges, Sew UV Edges, Move and Sew UV Edges, and others).

When a polygon face is currently selected the marking menu shows possibleUV modification operations for the selected UV type (for example,Normalize,Unitize, Layout, and others).

Related topics




■ Flip or rotate UV shells on page 79

■ Display UVs on page 31

■ Select UVs on page 32

UV setsYou can create multiple arrangements of UV texture coordinates for a surfacemesh using UV sets. UV sets are useful when an object requires multiple UVlayouts for different textures (known as multi-texturing).

For example, if you create a brick wall and want to layer spray paint on top,you can use one texture for the bricks and one texture for the paint using alayered texture. If the brick texture repeats but the paint texture doesn’t, youwill want different UV layouts (UV sets) for each.

If you are planning to pre-light the surfaces in your scene (also referred to aslight baking), you’ll want to use UV sets to store the shading and lighting color

UV sets | 11

information from the rendered appearance of a polygon mesh directly on thecolor per vertex information for the mesh.

The main steps to set up multi-texturing are:

■ Assign multiple textures to an object’s material.These textures can be assigned to different material attributes, such asColor and Incandescence, or assigned to a single attribute using a LayeredTexture node.

■ Create UV sets with different layouts.

■ Link each UV set to a given texture using the Relationship Editor.

Examples

The following examples show UV sets used to texture a brick wall. In bothexamples, the UV sets are:

■ unitizedUVs—for the repeating brick texture.

■ planarUVs—for the non-repeating texture.


UV sets for Color and Transparency

In this example, the UV sets are connected to textures on different attributesof the material—Color and Transparency.

UV sets for a Layered Texture

In this example, the UV sets are connected to layered textures.

UV sets | 13

Related topics

■ Create UV sets on page 83

■ Switch between UV sets on page 84

■ Duplicate, rename, or delete a UV set on page 84

■ Assign a texture to a UV set on page 85

■ Copy UVs from one UV set to another on page 86


Mapping UVs

Planar UV mappingPlanar mapping projects UVs onto a mesh through a plane. This projection isbest for objects that are relatively flat, or at least are completely visible fromone camera angle.

Planar mapping typically gives overlapping UV shells. The UV shells may beperfectly superimposed and look like a single UV shell. You should use Edit UVs> Layout after mapping to separate overlapping UVs.

The Best Plane Texturing Tool assigns UVs to the faces you select based on aplane computed from vertices you specify.

You can select the faces you want to map before you choose the Best PlaneTexturing tool, or you can choose the tool and then click each face you wantto map.

To map based on the best fit plane of the selection

1 Select the faces you want to map UVs onto.

2

15

2 Select Create UVs > Best Plane Texturing Tool.

3 You click faces to add them to the selection.

4 Select one or more faces on which you want to map the texture. Youcannot marquee-select the faces—you must select the faces one by one,or select the faces before using the operation.

5 Press Enter.

6 Select one or more vertices (press the right mouse button on the meshand choose Vertex to switch to selecting vertices).

7 Press Enter.

8 Use the UV Texture Editor to view and edit the resulting UVs.

To project from a plane defined by the view

1 Select the faces you want to project UVs onto.

2 Tumble the perspective view, or track an orthographic view to look atthe faces.

3 Select Create UVs > Create UVs Based On Camera.

16 | Chapter 2 Mapping UVs

To map based on a planar projection


2 Select Create UVs > Planar Mapping > .

The Planar Mapping Options window appears.

3 Set the following options as required:

■ Click Best Plane to position the manipulator based on the faces youselected.

■ Click Bounding Box to position the manipulator based on thebounding box of the mesh.

4 Click Project.

5 Use the projection manipulator to control how the plane distributes UVs.


Planar UV mapping | 17

You can also rotate the manipulator by clicking the red crossed lines,which reveals the Show Manipulator tool. Click the light blue circlearound the Show Manipulator handle to activate the rotate handles.

Notes

■ Planar mapping can create shared, overlapping UVs that can look liketexture borders. Turn on texture border display (in Display > Polygons >Texture Border Edges) to clearly show texture borders.

■ Shared, overlapping UVs can create seam problems if you paint over themwith the 3D Paint or Paint Fur Attributes Tools.To avoid these problems, manually separate the UVs with Edit UVs > Layout

> . Set Separate shells to Folds and the Shell layout option to Along Uor Into Square.


■ Projection mapping only works properly on a single object at a time. Ifyou need to apply a projection to multiple polygonal objects in a singlestep, combine the objects into one, apply the projection, and then separatethe parts back out. Otherwise, perform a projection on each objectseparately.

■ When a model’s form is very organic, and you require a complete UVrepresentation of that model for texture mapping, a planar projection canproduce UVs that overlap and appear distorted. Unless you want this tooccur it is recommended you try another UV mapping technique.

Related topics





■ Create UVs > Assign Shader to Each Projection on page 107

■ Create UVs > Create Empty UV Set on page 107

Cylindrical UV mappingCylindrical mapping creates UVs for an object based on a cylindrical projectionshape that gets wrapped around the mesh. This projection is best for shapeswhich can be completely enclosed and visible within a cylinder, withoutprojecting or hollow parts.

Cylindrical UV mapping | 19


2 Select Create UVs > Cylindrical Mapping.

3 Use the manipulator to change the position and size of the projectionshape.


NOTE Projection mapping only works properly on a single object at a time.If you need to apply a projection to multiple polygonal objects in a singlestep, combine the objects into one, apply the projection, and then separatethe parts back out. Otherwise, perform a projection on each object separately.


Related topics




■ Create UVs > Cylindrical Mapping on page 99

Spherical UV mappingSpherical mapping create UVs using a projection that is based on a sphericalshape wrapped around the mesh. This projection is best for shapes which canbe completely enclosed and visible within a sphere, without projecting orhollow parts.

To create UVs using a spherical mapping technique


2 Select Create UVs > Spherical Mapping.

3 Use the manipulator to change the position and size of the projectionshape.


Spherical UV mapping | 21

NOTE Projection mapping only works properly on a single object at a time.If you need to apply a projection to multiple polygonal objects in a singlestep, combine the objects into one, apply the projection, and then separatethe parts back out. Otherwise, perform a projection on each object separately.

Related topics





Automatic UV mappingAutomatic mapping creates UVs for a polygon mesh by attempting to findthe best UV placement by simultaneously projecting from multiple planes.This method of UV mapping is useful on more complex shapes where thebasic planar, cylindrical, or spherical projections do not produce UVs that areuseful, especially on components that project outwards or are hollow in nature.


Automatic mapping creates several UV map pieces or shells in texture space.This is fine if you are using tools that deal with UVs automatically for you,such as standard (not combed) fur and the 3D Paint tool in projection mode.If you need to work with the UVs manually, you will need to stitch the UVshells back together in the UV Texture Editor using the Move and Sew UVEdges feature.

You can also specify user-defined planes for the projection of UV texturecoordinates. The Load Projection option uses a polygon object you specifyfrom the current scene.

To facilitate more accurate UV projections a projection manipulator is displayedwhen using the Automatic Mapping feature. The projection manipulator letsyou correlate the multiple planar UV projections that occur in the scene viewwith how the resulting UVs appear in the UV Texture Editor.

Automatic UV mapping | 23

The projection manipulator appears centered about the selected object in thescene view with blue planes that correspond to the number of planes set bythe Automatic Mapping’s Planes option. A light blue color indicates that theprojection plane is oriented facing away from the selected object, while a darkblue plane indicates the side of the projection plane that is oriented facingtowards the selected object.

The manipulator’s planes are displayed semi-transparent at a scale of 50% ofthe actual projection plane so they don’t fully occlude the object when usingthe manipulator. Red and green lines appear along the edge of each plane toindicate the corresponding U and V axes within the UV Texture Editor.

You can move, rotate, and scale the UV projection manipulator just like othermanipulators in Maya. Scaling the manipulator affects the resulting scale ofthe projected UVs in the UV Texture Editor.

You can reset any transformations for the projection manipulator using theChannel Box. When a custom projection object is specified using the LoadProjection option, the projection manipulator gets updated to reflect theplanes specified by the custom projection.

To map UVs for a polygon object using Automatic Mapping

1 Select a polygon object in the scene view that you want to project UVstexture coordinates.

2 Select Edit UVs > UV Texture Editor to display the UV Texture Editor orselect the Persp/UV Texture Editor layout shortcut from the Toolbar toview the perspective view and the UV Texture Editor side by side.

When you project the UVs they will appear in the UV Texture Editor’s2D view.

3 From the Polygons menu set, select Create UVs > Automatic Mapping >

.

The Polygon Automatic Mapping Options window appears.

4 Set the following options depending on your requirements:

■ Set the Planes setting to the desired number of projections you requireand click Project. (The more planes you use, the less distortion in theUV layout but the more shells are created).

The automatic mapping projection manipulator appears centered aboutthe object in the scene view with blue projection planes that correspondto the Planes setting you specified. That is, if the Planes option was setto 4, then 4 planes appear on the manipulator.


5 To move, rotate, or scale the projection manipulator do the following:

■ To move the projection manipulator in X, Y, Z, drag any of the threecolored arrow handles while moving your mouse.

■ To rotate the projection manipulator, click the light blue circularrotate handle to make the X, Y, Z rotate handles appear. Draggingany of the three circles rotates the manipulator about X, Y, or Z.

■ To non-proportionally scale the projection manipulator, drag any ofthe three colored box handles on the manipulator.

■ To uniformly scale the projection manipulator, click any of the threebox handles on the tip of the manipulator so a 3D box appears. Dragthe box to scale the manipulator uniformly.


NOTE Projection mapping only works properly on a single object at a time.If you need to apply a projection to multiple polygonal objects in a singlestep, combine the objects into one, apply the projection, and then separatethe parts again Otherwise, perform a projection on each object separately.

Related topics





User-defined UV mappingYou can map UV texture coordinates by specifying user-defined planes for UVprojection using the Load Projection option within the Automatic Mappingfeature.

The Load Projection option uses a polygon object that you specify from thecurrent Maya scene. The object can form a cage around the object or becomprised of separate faces that intersect each other at its center. TheAutomatic Mapping projection manipulator updates when a user-definedobject is specified for projection.

User-defined UV mapping | 25

Criteria for user-defined projection objects

■ The object used as a user-defined projection object must have UV texturecoordinates.

■ It is recommended that the projection object be comprised of separatedpolygon faces. That is, a polygon primitive that gets used as a projectionobject should first be separated into separate meshes using Mesh > Extract.(NURBS and subdivision surfaces are not valid surface types for use withLoad Projection.)

In addition, it is useful to know that:

■ The UVs of the projection object determine the shape and location of thefinal projection mapping that occurs.

■ You can translate any face from the Load Projection object along its normalwith no affect on the resulting projection.

■ Scaling or rotating any face from the Load Projection object will affect theresulting orientation and scale of the final UV projection. The projectionmanipulator updates when this occurs.

■ The maximum number of polygon faces that can be specified for aprojection object is 31.

To load a user-defined polygon object for use with Automatic Mapping

1 Select a polygon object in the scene view that you want to project UVsonto.

2 Select Edit UVs > UV Texture Editor to open the UV Texture Editor.

The existing UVs for the object appear in the UV Texture Editor’s 2Dview.

3 From the Polygons menu set, select Create UVs > Automatic Mapping>

.

The Polygon Automatic Mapping Options window appears.

4 In the Polygon Automatic Mapping Options window, turn on the LoadProjection option, then do one of the following:

■ Specify the object in your current scene you want to have loaded asthe projection object by typing its name in the Projection Object box.


■ Select the object in your current scene that you want to have loadedas the projection object, and then click Load Selected. The name ofthe object appears in the Projection Object box. See Criteria foruser-defined projection objects on page 26 above.

5 Click Project or Apply to execute the Automatic Mapping feature.

The automatic mapping projection manipulator appears centered aboutthe object in the scene view with blue projection planes that correspondin orientation to the planes of the Load Projection object you specified.That is, if the Load Projection object has 8 planes in various angles oforientation, the projection manipulator displays similarly.

NOTE In some instances, the Load Projection object may cause the planeson the automatic mapping projection manipulator to appear unexpectedlyoffset or skewed from the object you’re projecting on. This UV offset is basedon the original UVs for the Load Projection object and doesn’t affect thequality of the projection.

You can unitize the UVs for the Load Projection object prior to projectionso its UVs reside in the 0 to 1 texture space. While this will make theprojection manipulator appear more centered about the polygon objectit may not provide the UV mapping results you were expecting as theUVs will be projected similar to having explicitly specified the Overlapfeature.

6 Translate, rotate, or scale the manipulator as required to achieve the UVprojections you require. The projected UVs appear in the UV TextureEditor. You can observe them update within the UV Texture Editorwhenever the manipulator is moved within the scene view.

Related topics





■ Create UVs > Spherical Mapping on page 100

User-defined UV mapping | 27

Confirm UV placementConfirming that UVs are positioned correctly for a surface mesh is critical ifyou want the textures to appear correctly on the surfaces of your mesh. Onemethod of confirming the UV placement is to assign a shader that containsa texture with visual characteristics that help indicate how the UVs aremapping the texture onto the surface.

When you turn on Create UVs > Assign Shader to Each Projection, Maya willassign a checkerboard texture shader to the mesh as you project UVs. Thisprovides a quick visual indication of the UV placement.

You can use a different texture on the defaultPolygonShader. For example, ifyou’re going to be mapping a stone texture to many objects, edit thedefaultPolygonShader to use a stone texture for previewing.

You can also create your own custom 2D image using a paint or 2D imagemanipulation application.

If you do not need to pre-adjust your texture maps, turn off Assign Shader toEach Projection. The option is off by default.

Related topics






Transfer UVs between meshesYou can map your UVs to a smoothed version of your polygon model, whereit may be easier to get good UVs (for example, you can smooth out wrinkleswhich cause overlapping UVs). Then you can use the Transfer operation tocopy the mapped UVs back onto the complex original model.

To transfer smoothed UVs between polygon meshes

1 Duplicate your polygon mesh.

2 On the duplicate, select the vertices you want to smooth.

3 Select Mesh > Average Vertices > .

4 Enter a value for the Smoothing Amount then click Apply.

The higher the value the more smoothing. You can click Apply repeatedlyto smooth repeatedly.

5 Project UVs onto the smoothed duplicate model using any of the mappingoptions in the Create UVs menu.

6 Use Mesh > Transfer Attributes to copy the UVs from the smoothedduplicated back to the original mesh.

Related topics

■ Mesh > Average Vertices

■ Mesh > Transfer Attributes

Transfer UVs between meshes | 29

30

Editing UVs

Display UVsUVs are viewed and edited in the 2D view of the UV Texture Editor (Edit UVs> UV Texture Editor). UVs display whenever a polygonal or subdivision surfacemesh is selected in the scene view. When the 3D mesh is de-selected the UVsare no longer displayed in the UV Texture Editor.

By default, all of the UVs for a selected object get displayed. You can display asubset of UVs using the Isolate Select feature. For more information see Displaya subset of UVs on page 33.

NOTE The 2D representation of UVs cannot be displayed in the Maya scene views.

To display UVs in the UV Texture Editor

1 Select Edit UVs > UV Texture Editor to display the UV Texture Editor.

2 Do one of the following:

■ In the scene view, set the selection type to object using the marking menuand then select the polygon or subdivision surface mesh.The UVs for the selected mesh are displayed in the UV Texture Editor.

■ In the scene view, set the selection type to UV using the marking menu andthen select any vertices on the polygon or subdivision surface mesh.The UVs associated with the vertices you selected on the mesh are displayedin the UV Texture Editor.

3

31

Related topics

■ Display a subset of UVs on page 33

■ Dolly or track within the UV Texture Editor on page 41

■ Display a texture behind the UVs on page 42

Select UVsSelecting UVs, UV components, and UV shells is critical to editing the layoutof UVs in the UV Texture Editor. You can select UVs in either the scene viewor in the UV Texture Editor but you can only view and edit the 2Drepresentation of UVs using the UV Texture Editor.

To select UVs in the scene view

1 Press the right mouse button over top of the polygon or subdivisionsurface mesh and select UV from the marking menu.

UVs for the surface mesh display in exactly the same location as thevertices so you can select them in the scene view.

2 Click on the UVs or drag a marquee selection to select the UVs.

The UVs are selected in the scene view. To view a 2D representation ofthe UVs you must open the UV Texture Editor (Edit UVs > UV TextureEditor).

To select UVs and UV shell components in the UV Texture Editor

1 Press the right mouse button on UVs in the UV Texture Editor to enterdifferent component selection modes.

This works in a similar fashion to how you select polygon componentswith the marking menu in the scene view.

32 | Chapter 3 Editing UVs

To convert an existing UV selection to another type

1 Hold Ctrl and press the right mouse button to show items for convertingone type of selection to another.

For example, if you have faces selected, you can convert the selection toUVs to use the Move tool, which only works with UVs. Use the items inthe UV Texture Editor’s Select menu to select various components:

■ Select Contained Faces: Selects the faces bordered the selected UVs oredges.

■ Select Connected Faces: Selects the faces connected to the selectedUVs or edges.

■ Select Shell: Select all UVs in the shell containing the current selection.This is useful to select the whole piece so you can move, scale, orrotate it.

■ Select Shell Border: Expands your selection to all UVs along the borderof the UV piece.

■ Convert Selection to Faces, Edges, Vertices, UVs: Converts the selectionfrom one type of component to another connected type. For example,if you have faces selected and convert selection to vertices, all verticesconnected to the faces are now selected.

Soft selecting UVs

You can use Soft Selection to smoothly transform textures on your modelswithout transforming each UV one at a time. Soft selection works bytransforming a falloff region around your selected region. For more informationsee Soft Selection.

Display a subset of UVsBy default, when you select a surface mesh Maya displays all of the UVs forthat mesh in the UV Texture Editor.

You can switch the UV Texture Editor between displaying all of the UVs forthe current set and only showing a selected subset in isolation. This makes iteasier to work on part of the model without disturbing or accidentally selectingother UVs.

Display a subset of UVs | 33

To isolate a specific subset of UVs

1 In the UV Texture Editor, if you already have a subset of UVs isolated,

click the Remove all button on the toolbar.

Alternatively, choose View > Isolate Select > Remove All.

2 Select the UVs you want to isolate.

3 Click the Toggle isolate select mode button on the toolbar, or chooseView > Isolate Select > View Set.

To switch back to showing all UVs, click Toggle isolation again, or turnoff the View > Isolate Select > View Set menu item.

To add to the isolated subset of UVs

1 In the UV Texture Editor, click the Toggle isolate select mode button on

the toolbar to switch back to showing all UVs.

Alternatively, choose View > Isolate Select > View Set.

2 Select the UVs you want to add to the isolated subset.

3 Click the Add selected button on the toolbar.

Alternatively, choose View > Isolate Select > Add Selected.

To remove UVs from the isolated subset

1 In the UV Texture Editor, select the UVs you want to remove from theisolated subset.

2 Click the Remove selected from isolation button on the toolbar.

Alternatively, choose View > Isolate Select > Remove Selected.

To display only the UVs that have the current image assigned

1 Show the texture (in the UV Texture Editor, choose Image > DisplayImage). If more than one texture is associated with the mesh, select thetexture you want to work on using the Textures menu.


When you are in component selection mode, the Textures menu listsshading groups assigned to the selected components. In object selectionmode, the menu lists all shading groups assigned to the entire mesh.

2 To only show faces with the current image assigned, in the UV TextureEditor turn on View > View Faces of Selected Images.

3 To show all faces again, turn off View > View Faces of Selected Images.

To display only the faces inside the selected UVs or edges

1 Select UVs or edges to define a border.

2 In the UV Texture Editor, turn on View > Contained Faces.

3 To show all faces again, turn off View > Contained Faces.

To display only the faces that share the selected UVs or edges

1 Select UVs or edges.

2 In the UV Texture Editor, turn on View > Connected Faces.

3 To show all faces again, turn off View > Connected Faces.

Move, rotate, and scale UVsYou can manually move, scale, or rotate UVs and UV shells in the UV TextureEditor. For example, you may wish to move individual UVs or entire UV shellsto improve their layout, or scale UV shells to ensure they make optimal useof the 0 to +1 texture space.

Do this:To...

Use the appropriate tool.Move, rotate, or scale UV positions.

1 Select the UVs you want to re-position.

2 Select the Move, Rotate, andScale tools from the Toolbox.

Note: Scaling UVs of multiple polygonalobjects together in the UV Texture Editor

Move, rotate, and scale UVs | 35

Do this:To...

may produce unexpected results. Work onthe UVs of one object at a time.

Use the Move UV Shell Tool.Move a UV shell and ensure that it doesnot overlap other shells.

1 From the UV Texture Editormenu, select Tool > Move UV

Shell Tool > . (Or click theMove UV Shell Tool icon onthe toolbar of the UV TextureEditor.

2 Select the UV shell you wantto move by either clicking theshell or dragging a boundingbox around it in the UV Tex-ture Editor.

3 Drag the manipulator to movethe UV shell.

Note: To prevent the repositioned shellfrom overlapping other shells, turn on thePrevent overlap option. See Tool > MoveUV Shell Tool on page 150.

Use the Rotate UVs options.Rotate UVs by an exact number.

1 Select the UVs you want to ro-tate.

2 Select Edit UVs > Rotate > .

3 Enter a number for the rotationangle and click Rotate or Ap-ply.

Use the Flip UVs options.Flip UVs to flip the texture placement onthe mesh.

1 Select the faces you want to fliptexture placement on.


Do this:To...

2 Select Edit UVs > Flip > .

3 Select the Direction and Co-ordinate system on which toflip and click Apply and Closeor Apply.

Use the Normalize UVs options.Scale UVs to fit within the 0 to +1 texturerange. 1 Select the faces whose UVs you

want scaled within the 0 to 1range in the UV Texture Editor.

2 Edit UVs > Normalize > .

3 Select the method which youwish to normalize with andclick Apply and Close or Apply.

Use the Unitize UVs options.Move UVs to (0,0), (1,1), (1,0), or (0,1) intexture space.

1 Select the faces whose UVs youwant to have unitized.

2 Select Edit UVs > Unitize > .

3 Adjust the settings as desiredand click Apply and Close orApply.

Discrete Rotate and Scale

You can use Discrete rotate and Discrete scale to rotate or scale your UVs byfixed increments. You can modify these increments in the Step size field. Thisis useful to restrict the rotation or scale amount to a specific factor.


Discrete rotate or Discrete scale can be found in the Tool Settings Editor whenthe Rotate Tool or Scale Tool are selected respectively.

To use Discrete rotate or Discrete scale

1 Select the UVs you want to rotate or scale in the UV Texture Editor.

2 Double-click either the Rotate Tool or Scale Tool from the Toolbox.

The Tool Settings Editor appears.

3 Turn on Discrete rotate or Discrete scale.

4 Adjust the Step size.

5 Use the manipulators to rotate or scale your object.

The object rotates or scales in set increments.

UV Snapping

You can use snapping in the UV Texture Editor to transform UVs with greatprecision the same way you can use it to transform components in the sceneview.

Related Topics

■ Snap to the grid, a curve, points, or a view plane


■ The pivot point

■ Rotate Tool

■ Scale Tool

Example 1: Snapping to projections

When Snap to Points is on, you can also snap to UV projections along the Uor V axis. A UV projection is a straight line in either the U or V direction froma UV. This is useful if you don’t want to snap two UVs together, but wantthem to line up in the UV Texture Editor.


You can use this functionality on multiple UVs at once to obtain differentresults.

With the Retain Component Spacing option off, all the selected UVs snap tothe nearest UV projection. Notice below that the selected UVs line up withthe circled UV beneath them when translated right.

With the Retain Component Spacing option on, the center of the selectedUVs snaps to the nearest UV projection. The relative spacing of the selectedUVs is maintained. Notice below that the shape of the selected UVs ismaintained and only the center of the selection (the manipulator) lines upwith the circled UV beneath them when translated right.

The behavior of snapping to UVs and UV projections depends on the UV SnapTolerance setting in Window > Settings/Preferences > Preferences in theSnapping section under Settings.

Example 2: Pivot snapping

You can use snapping in the UV Texture Editor to position pivots for rotationor scaling. This helps to reduce the number of steps in some workflows andensures that transformations along existing points are accurate.


For example, if you want to rotate the upper portion of a cube’s UV shell 90degrees around its bottom left corner, you can rotate it first, then translate itleft.

However, it’s easier and more precise to move the pivot point to the bottomleft corner and rotate on that pivot.

To rotate around a UV

1 Select the UVs you want to rotate.

2 Select the Rotate Tool from the Toolbox.

3 Press Insert or Home.

The manipulator changes to the move pivot manipulator.


4 Hold v on your keyboard or select the Snap to Points option in the statusline.

5 Move the pivot to the UV you want to rotate around.

When you move the manipulator close to a UV, the pivot automaticallysnaps to it. You can then move the pivot from UV to UV.

6 Press Insert or Home to return to the rotate manipulator

7 Rotate the UVs.

You can use a similar workflow to scale a set of UVs relative to a specific point.

Dolly or track within the UV Texture Editor

Do thisTo...

Use the camera move keys:Change the view of the UVs.

■ alt + the middle mouse button to track

■ alt + the right mouse button to dolly in and out

In the UV Texture Editor, choose View > Frame All.Zoom in/out to show all UVs.

In the UV Texture Editor, choose View > Frame Selec-tion.

Zoom in/out to show the selec-ted UVs.

In the UV Texture Editor, click the Toggle TextureBorders button.

Make texture borders look thick-er.

Related topics


■ Separate and attach UV shells on page 52

Dolly or track within the UV Texture Editor | 41

Display a texture behind the UVsYou can display the image associated with a texture in the UV Texture Editor.The image appears behind the UVs so you can rearrange the UVs in relationto the image.

Do thisTo...

In the UV Texture Editor, click the Toggle Image but-ton on the toolbar or select Image > Display Image.

Display the texture image be-hind the UVs.

In the UV Texture Editor, click the Toggle Image Ratiobutton on the toolbar or select Image > Use ImageRatio.

Set the image ratio.

In the UV Texture Editor, click the Toggle Filtered Pixelsbutton on the toolbar or select Image > Display Un-filtered.

Switch between blended andsharp-edged pixels.


Do thisTo...

Select the mesh object to show a mesh texture, orfaces to show per-face textures.

Switch between showing amesh texture and a per-facetexture.

In the UV Texture Editor, select the texture you wantto work on from the Textures menu.

Choose a texture to display (ifmore than one texture is ap-plied to the mesh). When you are in component selection mode, the

Textures menu lists shading groups assigned to theselected components.In object selection mode, the sub-menu lists all shad-ing groups assigned to the entire mesh.

In the UV Texture Editor, choose Image > Image Range

> .

Crop the image within UV co-ordinates.

If the texture quality is poor or if parts of the texture do not display correctly,you can modify the display quality with the Hardware Texturing settings inthe Attribute Editor for the material node.

If you are using a file texture, the best display mode for the Texture resolutionsetting is Default. (The other settings, such as High, are best for proceduraltextures.)

If you experience resolution or cropping problems in the texture image display,use Image > UV Texture Editor Baking to bake the texture. You must rebakethe texture (using UV Texture Editor toolbar on page 154) after making changesto the texture (File node and place2dTexture node attributes) in order to seethe effect of those changes.

Related topics



Delete UVsDelete UVs removes UV texture coordinates from the selected face(s). Whenyou select a face on the mesh that has an assigned texture and delete the UVs,

Delete UVs | 43

the assigned texture doesn’t appear any longer on the face(s) where the UVswere deleted. You can re-create the UVs for the selected faces (or the entiremesh) using the UV projection mapping operations.

Deleting UVs removes only the UV texture coordinate data on the mesh anddoes not affect the vertices on the mesh.

To delete UV texture coordinates for a selected face

1 In the scene view, select the face(s) for which you want to delete the UVs.

2 Select Edit UVs > Delete UVs. (If you are working in the UV Texture Editoryou can select Polygons > Delete UVs.)

The UVs associated with the selected face(s) are deleted.

Because the selected faces have no UVs, textures cannot be applied to themuntil UVs are re-created.

NOTE When you select one UV in the UV Texture Editor and select Polygons >Delete UVs, all of the UVs for the face(s) associated with the UV you selected alsoget deleted. For this reason, the Delete key on the keyboard does not delete UVsbecause of the unique requirements of this operation.

Related topics

■ Edit UVs > Delete UVs on page 137






Update a texture image after UV modificationWarp Image modifies a texture image by comparing two UV sets on a singlepolygonal mesh and produces a new bitmap image. To use this feature youmust specify a source image, as well as a source and destination UV set for themodel from which the UVs will be referenced for the image manipulation.Warp Image produces a new target image as the result.

You choose Warp Image by selecting Edit UVs > Warp Image from within thePolygons menu set or from the Polygons menu in the UV Texture Editor.

Warp Image is useful in the following situations:

■ When you don’t want to manually regenerate an image for an existingtexture map when the UVs for the texture have been changed. Warp Imagewill calculate where the pixels should be relocated and update the texturefor you. This is helpful when the UVs on a polygonal mesh have beenrefined in some way. For example, if it were necessary to cut, merge, oroptimize the UVs for some reason, the way an associated texture map wasdisplayed on the polygon object would be affected as a result.

■ Creating more texture space for key areas in a texture map. For example,when texture mapping a face, the UVs surrounding the eyes and mouthcan be scaled larger so there are more pixels assigned to these areas in thefinal texture map. If you scaled the UVs within the UV Texture Editor tooptimize the texture space, you can warp the associated image to accountfor the modified UVs.

NOTE Warp Image may not produce as high quality an image as you expect.It may be necessary to perform additional post processing work on the image.

Warp Image requires two UV sets in order to produce a new image (in additionto the original image). Unless you have previously created a UV set for thepolygonal mesh it is highly recommended that prior to doing any UV editingwithin the UV Texture Editor, you explicitly save a copy of the original UVsfor the textured polygonal mesh as a UV set by selecting Polygons > CopyUVs to UV Set > Copy into New UV Set. In that way you’ll have the originalUV set to revert back to should you require it.

Update a texture image after UV modification | 45

Prior to warping an image, two UV sets must exist for the polygonal mesh:the existing UV set from which the original texture is assigned, and a secondUV set that will be referenced for modifying or warping the image. The twoUV sets will be referenced as the Source and Destination UV sets.

To warp an image based on updated UVs


■ From the Polygons menu set, select Edit UVs > Warp Image > .

■ In the UV Texture Editor, select Polygons > Warp Image > .

The Warp Image Options window appears.

2 Type the file name for the source image you want to warp in the SourceImage Name field or browse to the location and select the file name.

3 Type the file name for the new image you want created by Warp Imagein the New Image Name field or browse to select a location and imagename.

4 Type the names of the Source and Destination UV sets that you want theWarp Image feature to reference. If you forget the names of the UV sets,they can be viewed in the UV Texture Editor by selecting the UV Setsmenu and viewing the UV set names in the drop-down list.

5 Set any remaining options that you want and then click Warp Image.

6 Warp Image calculates the new pixel positions for the new image andoutputs the image to the location you specified.

To view the new texture on your surface mesh you must edit the currentlyassigned shader to use the new image. Ensure that you have the correctUV set applied to the mesh so you see the results you expect.

Related topics

■ Edit UVs > Warp Image on page 115


Use the UV Texture Editor gridThe UV Texture Editor has a grid feature that lets you accurately control theposition and spacing of UVs when you move, rotate, or scale them.

Do thisTo...

In the UV Texture Editor, click the ToggleGrid button on the toolbar or choose View> Grid.

Show or hide the grid.

In the UV Texture Editor, right click theToggle Grid button on the toolbar or

choose View > Grid > .

Change the grid.

Use grid snapping (hold x).Snap UVs to the grid.

Double-click the Move tool to open itsoptions panel.

Change how UVs snap.

Use the Retain Component Spacing optionto control how UVs snap:When off, all selected UVs will snap to thesame point.When on, selected UVs will keep their pos-itions relative to each other as they move.

In the UV Texture Editor, click the ToggleSnap to Pixel button in the toolbar, orchoose Image > Pixel Snap.

Snap UVs to pixels.

Use the UV Texture Editor grid | 47

Do thisTo...

To control whether snapping is to pixelcorners or centers, display the Move Tooloptions, (make sure focus is on the UVTexture Editor) and set Placement to SnapCorner or Snap Center.

Related topics



Save an image of the UV layoutAfter you create a final layout of your UVs in the UV Texture Editor, you canexport an image of the UV shells using UV Snapshot. UV Snapshot saves abitmap image of the UV Texture Editor’s 2D view at a user defined resolution.You can use the image in the Maya® Paint EffectsTM canvas or image editingapplication such as Adobe® Photoshop®, and paint a texture to match theUVs.

UV Snapshot works with multiple selected objects and has the ability to extendthe region of the snapshot area to encompass the entire range of the selectedUV texture coordinates, regardless of whether the UVs belong to a polygonalor subdivision surface type. UV Range options let you specify the region ofthe UV Texture Editor’s view you want to have captured for the output image.

UV Snapshot is also available from the Subdivs menu in the UV Texture Editorto facilitate an easier workflow when working with subdivision surfaces.

To save an image using UV Snapshot

1 In the scene view, select the mesh or components so their UVs appear inthe UV Texture Editor.

2 In the UV Texture Editor, choose Polygons > UV Snapshot.

(You can also select UV Snapshot from the Subdivs menu in the UVTexture Editor)

3 Enter a name in the File name field that you want to export to.


4 Set the size of the image using the Size X and Size Y fields.

5 Choose a Color value for the UV edges.

Unless specified, the background color for the image will be black.

6 Choose an Image format.

7 Set the UV Range Options.

8 Click OK.

Related topics

■ UV Texture Editor reference on page 139

■ UV Texture Editor menu bar on page 140

■ UV Texture Editor toolbar on page 154

Modify UVs using the UV Lattice ToolYou can modify the layout of multiple UVs at once on polygonal or subdivisionsurface geometry using the UV Lattice Tool in the UV Texture Editor.

The UV Lattice Tool gives you a high level of control over your UVs by lettingyou edit the layout of numerous UVs at a time with a 2D lattice deformer.

To edit the layout of your UVs using the lattice manipulator

1 In the scene view, select the polygonal or subdivision surface object whoseUVs you want to manipulate.

2 Select Edit UVs > UV Texture Editor.

The UV Texture Editor appears.

3 In the UV Texture Editor’s view, switch to UV mode.

Right-click in the view and select UV from the marking menu that appears.

4 In the UV Texture Editor menu bar, select Tool > UV Lattice Tool > .

The UV Lattice Tool Options window appears.

5 Set the UV Lattice Tool options and then click Apply and Close.

Modify UVs using the UV Lattice Tool | 49

6 Select Tool > UV Lattice Tool or click the UV Lattice Tool buttonin the UV Texture Editor toolbar.

7 In the UV Texture Editor view, drag around the UVs you want tomanipulate. This selects the target UVs for the lattice.

A UV lattice manipulator appears over and surrounding the target UVs.

8 Select the lattice edges or control points that affect the region of UVs youwant to manipulate by clicking them.

Shift-click lattice edges or control points to include them or remove themfrom your selection.

9 Drag the selected lattice edges or control points to deform the layout ofthe target UVs.

Related topics





Modify UVs using the UV Smudge ToolYou can drag or smudge the layout of UVs on your polygonal or subdivisionsurface geometry using the UV Smudge Tool in the UV Texture Editor.

The Smudge Tool gives you a high level of control over your UVs, providinga more free-form approach to manipulating the layout of your UVs.

To smudge the layout of your UVs

1 Select the geometry whose UVs you want to manipulate.

2 Select Edit UVs > UV Texture Editor.

The UV Texture Editor appears.

3 In the UV Texture Editor menu bar, select Tool > UV Smudge Tool > .

The UV Smudge Tool Options window appears.

4 Set the UV Smudge Tool options as required and then click Apply andClose.

5 Select Tool > UV Smudge Tool or click the UV Smudge Tool buttonin the UV Texture Editor toolbar. The following occurs:

■ The UV Texture Editor’s view switches to UV mode.

■ All the UVs of the current geometry become selected.

■ The UV Smudge Tool brush appears in the UV Texture Editor’s view.

6 If the Middle Mouse Initiates tool setting is off, do one of the following:

■ In the UV Texture Editor’s view, drag to smudge the layout of all yourUVs.

■ In the UV Texture Editor’s view, Shift-drag around the UVs you wantto select and then drag to smudge the layout of the selected UVs.

Modify UVs using the UV Smudge Tool | 51

If the Middle Mouse Initiates tool setting is on, do one of the following:

■ In the UV Texture Editor’s view, middle-drag to smudge the layoutof all your UVs.

■ In the UV Texture Editor’s view, drag around the UVs you want toselect and then middle-drag to smudge the layout of the selected UVs.

Related topics




Separate and attach UV shellsMaya provides several features for separating, merging, and attaching UVs.These features can be particularly useful when working with UVs that weregenerated using the Automatic Mapping feature.

Do thisTo...

Select Edit UVs > Cut UV Edges.Separate a UV shell along the selectededges.

Select Edit UVs > Sew UV Edges.Attach UV shells along the selected edges.


Do thisTo...

Select Edit UVs > Move and Sew UV Edges

> . Turn off Limit Shell Size and clickApply.

Attach UV shells along the selected edgesand move the shells together.

Select Edit UVs > Merge UVs.Merge the selected UVs.Merge UVs only merges the UVs that sharethe same vertex. You can specify an optionfor the maximum distance Maya will moveUVs to merge them.

Select all the shells and choose Edit UVs >

Move and Sew UV Edges > .

Automatically attach and move small shells.

Turn on Limit Shell Size and set the maxim-um size (in number of faces) for UV shells.Shells larger than this number will notmove.Click Apply.

After performing a Move and Sew UV Edges operation, you can select the node(polyMapSewMove) and edit it in the Attribute Editor or Channel Box to adjustthe Number Faces.

Separate and attach UV shells | 53

Notes

■ A single edge cannot be cut unless it touches a border.

■ Use the Select > Select Shell in the UV Texture Editor to select a UV pieceafter cutting.

Related topics

■ Display overlapping UVs on page 54

Display overlapping UVsThe Shade UVs feature lets you see whether any UVs or UV shells overlapwhen viewed in the UV Texture Editor. You can also see the UV winding orderon the selected UV shells. For more information on UV winding order seeDisplay UV winding order on page 55.

When Shade UVs is turned on any selected UV shells appear shaded in asemitransparent way. Areas where shading appears more opaque indicate theregions of overlap. Overlapping UVs are often undesirable because anyassociated texture maps will also overlap on the related surface meshes.


To display overlapping UVs in the UV Texture Editor

1 In the UV Texture Editor, select any UVs or UV shells whose display youwant to appear as shaded.


■ In the UV Texture Editor menu, select Image > Shade UVs > .

The UV Map Shading Options window appears to let you modify thedefault settings for color and opacity. For more information see Image >Shade UVs on page 151.

■ Click the Shade UVs icon ( )located on the toolbar of the UVTexture Editor.

The selected UV shells update to a semitransparent shaded display. Areaswhere the UVs or UV shells overlap are visually apparent by the increasedopacity of the shading in the overlapping regions.

TIP You can correct overlapping UVs and UV shells using the Unfold and theLayout features. For more information see Layout UV shells on page 58.

You can also view the texture borders for a UV shell by selecting Display> Polygons > Texture Border Edges.

Related topics



■ Unfold a UV mesh on page 65

■ Layout UV shells on page 58

Display UV winding orderYou can visually determine the winding order on UV shells when you workin the UV Texture Editor using the Shade UVs feature.

Display UV winding order | 55

When the Shade UVs feature is turned on, selected UV shells whose UVwinding order is clockwise will appear shaded with a semi-transparent bluecolor. UV shells whose UV winding order is counterclockwise will appearshaded with a semi-transparent red color.

The UV winding order refers to the direction in which UV texture coordinatesare stored on the surface mesh for a particular face. This direction can be eitherclockwise or counter-clockwise and is important to know when texturemapping polygon meshes because it can affect whether a texture maps correctlyor not.

Texture maps can appear flipped or reversed on a polygon mesh dependingon how the UV shell is wound. The UV winding order can be reversed for thefollowing reasons:

■ The original UV mapping used to create UV texture coordinates may haveproduced an incorrect UV winding order. For example, if you map a cubeusing planar UVs, the UV winding will be clockwise on the UV shell closestto the projection plane and counterclockwise on the UV shell on the faceon the opposite side of the cube.

■ When the normals are flipped on a face of a polygon mesh, the UV windingorder on the face is reversed.


To display the winding order on UVs in the UV Texture Editor

1 In the UV Texture Editor, select any UVs or UV shells whose windingorder you want to determine.


■ In the UV Texture Editor menu, select Image > Shade UVs.

■ Click the Shade UVs icon located on the toolbar of the UV TextureEditor.

The selected UV shells appear shaded and semitransparent. Shells witha clockwise winding order (front facing) appear shaded in blue. Shellswith a counter-clockwise winding order (back facing) appear shaded inred. Areas where the UV shells overlap are visually apparent by theincreased opacity of the shading in the overlapping regions.

3 Any UV shells that display with incorrect UV winding can be modifiedusing the Flip UVs feature. For more information see Flip or rotate UVshells on page 79.

NOTE You can modify the default settings for color and opacity for the Shade

UVs feature by selecting Image > Shade UVs > . For more information seeImage > Shade UVs on page 151.

Display UV winding order | 57

Related topics




■ Image > Shade UVs on page 151

■ Tangent Space

Layout UV shellsThe Layout feature automatically repositions UV shells so they don’t overlapin UV texture space and maximizes the spacing and fit between them. This isuseful for ensuring that the UV shells occupy their own separate UV texturespace. For example, if you are applying Fur to a surface, the UV texturecoordinates on a given shell must not overlap.

In general, you should keep UV shells separated for convenience and clarity.It is not absolutely necessary to keep UV shells separate. For example, youmay want the UV shells to overlap so different faces use the same region of atexture.

You can also use the Layout feature to:

■ Scale or stretch the UV shells to fit within the 0 to 1 coordinates of the UVTexture Editor. This is useful if you need to maximize the texture spaceused when creating a texture map. For example, when using 3D Paint.

■ Flip UV shells that correspond to opposite sides of a model. Thisautomatically corrects the orientation of the UV shell if the UV windingorder is incorrect. See Display UV winding order on page 55.


■ Arrange the UV layout of multiple selected objects simultaneously. Thisimproves your efficiency when you need to quickly sort the UVs formultiple objects within the UV Texture Editor, or when multiple objectsneed to share different parts of the same texture.By default, when Layout is used with multiple objects, the UVs for eachobject are placed individually. As a result, they overlap each other withinthe UV Texture Editor. This saves you the work of having to lay out eachUV set individually. When the Layout Multiple Objects option is set toNon-Overlapping, the UVs are laid out as if all of the objects were combinedas one.

The Layout feature is also available from within the UV Texture Editor byselecting Polygons > Layout from the UV Texture Editor’s menu bar.

NOTE Before using Layout you should already have performed the necessaryUV projection mapping or Automatic Mapping. That is, the Layout feature willonly arrange existing UV texture coordinates, it will not create them.

To lay out UVs for multiple objects simultaneously

1 Select the objects or faces whose UVs you want to lay out.

2 Select Edit UVs > UV Texture Editor to display the UV Texture Editor.

3 In the UV Texture Editor, select Edit UVs > Layout> .

The Polygon Layout Options window appears.

4 In the Layout UVs Options window set the following options dependingon your required outcomes:

■ Set Layout objects to Per Object (overlapping) (default) when yourequire multiple object’s UVs to overlap within the UV texture space.

■ Set Layout objects to Single or Multiple Objects (non-overlapping)when you require the UVs to be separated. This is useful when youneed each UV set to be separate and distinct from each other.

■ Set Prescale to Object to maximize the spacing and fit between theUV shells.

■ Set the Shell Stacking option to adjust the spacing between UV shellsby specifying how the bounding shape for the UV shells will bedescribed. In general, the UV layout will have more space when theBounding Box option is set, and less space when the Shape option is

Layout UV shells | 59

set. When the Scale Mode is set to Uniform the shells are scaled tomake optimal use of the UV texture space.

5 Click Apply to perform the layout operation or Layout UVs if you wantto perform the operation and close the Layout UVs Options window.

Related topics


■ Edit UVs > Layout on page 129


Map border UVs to a square or circlePrior to relaxing any interior UVs on a shell you should attempt to untanglethe border UVs on the exterior of the UV shell. You can do this using the MapUV Border feature and with the Straighten UV Border feature.

When you use Map UV Border you can move the UVs on the border of a UVshell out to the edges of the 0 to 1 texture space range (square), or in a circleinscribed within the 0 to 1 range. Mapping UVs so they use the entire 0 to 1texture range is useful when you need to maximize the texture space requiredfor a texture map.

You can optionally scale the edges proportionally as you move the borderUVs. This is useful for untangling borders before you use Relax UVs to untangleinterior UVs.


To map border UVs to a square or circle

1 Select one UV on the shell whose border UVs you wish to map. The UVyou select will represent the lower left corner of the square or circle bordermap you wish to make.

The UV you select is important as it will determine where the UV shellwill be mapped to the 0,0 origin of the UV texture space. If the resultingUV border mapping appears skewed, you may wish to undo it, and selectanother UV and map again.

2 Select Edit UVs > Map UV Border > .

Map border UVs to a square or circle | 61

If you are using the UV Texture Editor, you can select Polygons > Map

UV Border > .

3 Set the options, then click Map or Apply.

The border UVs are mapped based on the settings you made. The interiorUVs will remain unchanged. You can untangle the interior UVs usingthe Relax UVs feature.

4 If the UV mapping appears correct, you can use the Relax UVs feature tountangle the interior UVs on the shell.

Related topics

■ Edit UVs > Layout on page 129

■ Straighten border UVs on page 62

■ Relax and untangle UVs on page 63

Straighten border UVsStraighten UV Border is useful when you want to untangle the border of a UVshell, such when the border edge loops around itself. Straighten UV Borderprovides more control than the Map UV Border operation.

To straighten border UVs

1 In the UV Texture Editor right-click and select UV from the markingmenu.

2 Select the UVs around the tangled UV border.


It doesn’t matter if you select interior UVs along with border UVs.Straighten UV Border only acts on the borders.

In some cases, it is difficult to select the UVs you want to straightenwithout selecting other UVs you want to leave unaffected. In these cases,you can leave a gap in your selection and use the Fill Gaps in Selectionoption to straighten the UVs you could not select.

3 Select Edit UVs > Straighten UV Border.

If you are using the UV Texture Editor, you can select Polygons >

Straighten UV Border > .

4 Select the polyStraightenUVBorder node and edit the attributes in theAttribute Editor or Channel Box.

Related topics


■ Edit UVs > Straighten UV Border on page 120

Relax and untangle UVs

Relax a UVs to untangle and even out the spacing between UV coordinateson a shell. Relax is useful for untangling interior UVs in combination withthe Map UV Border feature. You can begin by mapping the UVs to a border(either a square or a circle) then relax the UVs to even out the spacing of theUVs.

You can relax UVs using the Smooth UV Tool or the Relax feature, each withtheir own applications.

The Smooth UV Tool allows you to view the affected UVs as you relax them.This is useful for making precise visual adjustments. You can also use this toolto relax either the entire UV shell or only a subset of UVs on it.

While both the Smooth UV Tool and the Relax feature allow you to pin theborders of your UV shell so they don’t move, the Relax feature has additionaloptions that let you pin selected or unselected UVs while relaxing all theothers. The Relax feature always applies to the entire shell.

Relax and untangle UVs | 63

To relax UVs on a shell

1 From the UV Texture Editor, select a set of UVs.

2 Select Tool > Smooth UV Tool or select from the UV Texture Editortoolbar.

Two small controls appear at the bottom-left of the selected UVs.

3 Click the box labelled Relax and drag the mouse right. The further youdrag, the more the selected UVs relax.

NOTE You can move the Unfold and Relax controls by dragging the yellow targeticon at the top left of the controls.

With the Smooth UV tool you can choose to relax the entire mesh or onlypart of it. However, you cannot use it to relax multiple UV shells at once.Additionally, there may be instances when you need more control over someaspects of the relax process. For example, when relaxing UVs you may wantto pin specific UVs. You can do this with the Relax option.

To relax UVs using the Relax feature

1 Select one UV on the shell whose UVs you want to untangle (relax).

2 Select Edit UVs > Relax > .

If you are using the UV Texture Editor, select Polygons > Relax > .


3 Select the options, then click Relax or Apply.

You can apply Relax multiple times to move the UVs more.

Related topics

■ Map border UVs to a square or circle on page 60

■ Edit UVs > Relax on page 121

Unfold a UV mesh

The Unfold feature lets you unwrap the UV mesh for a polygonal object whileattempting to ensure that the UVs do not overlap. Unfold helps to minimizethe distortion of texture maps on organic polygon meshes by optimizing theposition of the UV coordinates so they more closely reflect the original polygonmesh. For example, if the initial shape of the UVs cause a patterned textureto distort, you can use the Unfold feature to minimize the distortion becauseit attempts to maintain the UV’s relationship relative to the original polygonmesh.

You can access Unfold by:

■ selecting the Smooth UV Tool (Tool > Smooth UV Tool in the UV TextureEditor).

Unfold a UV mesh | 65

■ selecting Edit UVs > Unfold from within the Polygons menu set or fromwithin the UV Texture Editor by selecting Polygons > Unfold

Unfold works well in situations where UV meshes need to be created frompolygonal models that have complex organic shapes. In these situations, otherprojection methods may not be as successful and automatic mapping wouldproduce too many individual UV shells that would necessitate many moveand sew operations afterwards. For example, polygon models that are proneto overlap via other projection methods would be well suited for the Unfoldfeature.

When compared to Automatic Mapping, Unfold produces good UVs on largerUV shell areas because it keeps neighboring faces together (by contrast,Automatic Mapping produces many separate UV shells).

Unfold is not needed when working with simple, non-organic poly meshforms. In these cases, other projection techniques or automatic mapping wouldbe better suited and more straightforward. For example, a wall can beplanar-projected or a bottle can be cylindrically projected.

Unfold setup

Prior to using the Unfold feature you should consider the following:

■ The polygon mesh must have UV texture coordinates.The mesh must first have UVs to unfold. You can create UVs using almostany mapping technique (for example, cylindrical mapping, sphericalmapping, and so on). In general, the initial shape of the UVs doesn’t affectthe final unfolded result. However, their initial shape should be asdistortion free as possible to avoid long computations when unfoldingand to facilitate UV edge selection for cuts.

■ The UV mesh must be cut in a manner that allows the Unfold feature tofreely unwrap the UV mesh.


When unfolded, the polygon mesh should be able to lay relatively flatwithout overlapping. Imagine cutting a shirt along its sides so that itspattern lies flat over a table. Like this example, in Maya you must cut edgesfrom the original shell to unfold a UV texture.


Locating the edge cuts requires some planning, in advance of the actualcuts, to obtain the best unfolded result. The better the edge cuts, the betterthe correlation between the original polygons and their corresponding UVmesh. In addition, you should anticipate that the polygon edge cuts willresult in texture mismatches along edges, and locate edges on the modelwhere they are least visible. For example, make edge cuts under the armsor on the back of the legs of a character.

■ Consider the UVs you want to pin.When unfolding a UV shell, it is important to consider where you areunfolding relative to. A pinned UV provides an anchor around which otherUVs can be unfolded. Often, if you do not pin at least one point whenunfolding a UV shell, the shell will unfold into a very tiny mesh or intoan undesirable shape. For symmetrical meshes, you often want to pin aUV along the line of symmetry.

For more information about pinning, see Pinning on page 71.

When using the Smooth UV Tool, any unselected UVs are automaticallypinned. Conversely, when using the Unfold command, you can chooseto pin any selected UVs or unselected UVs.

To prepare a UV shell for unfolding

1 Ensure the polygon model you are working with has UVs. To do this,

perform an initial UV mapping operation on the mesh to produce a UVtexture mesh (for example, using Create UVs > Cylindrical Mapping).

NOTE The shape of the UV texture mesh is not critical at this stage becausethe Unfold feature will modify it.

2 In the scene view, determine the locations where you will perform edgecuts on the UV texture mesh using the 3D polygonal model as a reference.Dollying and tumbling the scene view helps you with this task.

For additional tips on determining edge cuts, see UV unfolding workflowtips on page 70.

TIP When editing UVs you can use the perspective view and the UV TextureEditor, side by side, to locate and select or deselect the polygon vertices,edges, and UVs. To do this, right-click on any layout shortcut in the Toolboxand select Persp/UV Texture Editor from the drop-down list.

3 In the scene view you can select vertex edges that lie in a contiguous lineby double-clicking one of the edges on the line. You can also select a path


of edges between two points using the Select > Select Shortest Edge PathTool.

4 Using both the 3D view and UV Texture Editor as required, continue toselect and cut the edges of the UV mesh in the locations youpredetermined earlier using Polygons > Cut UV Edges in the UV TextureEditor.

5 Find and make note of the UVs you want to pin.

Once you are satisfied with the cuts you’ve made, you are ready to unfold theUV shell.

To unfold a set of UVs

1 From the UV Texture Editor, select a set of UVs. Any UVs you leaveunselected will be pinned when you unfold the mesh.

2 Select Tool > Smooth UV Tool or select from the UV Texture Editortoolbar.

Two small controls appear at the bottom-left of the selected UVs.

3 Click the box labelled Unfold and drag the mouse right. The further youdrag, the more the selected UVs unfold.

NOTE You can move the Unfold and Relax controls by dragging the yellow targeticon at the top left of the controls.

With the Smooth UV tool you can choose to unfold the entire mesh or onlypart of it. However, you cannot use it to unfold multiple UV shells at once.


You may also want to control specific aspects of the Unfold operation. Youcan do this with the Unfold option.

To unfold a polygon UV texture mesh using the Unfold feature

1 In the UV Texture Editor, select the polygon UV mesh, and then selecting

Polygons > Unfold > .

2 Select the options you want and then click Apply and Close.

3 When you want to stop the Unfold operation, press Esc.

In general, the Unfold operation requires several iterations to achievethe desired final result. It may often be necessary to refine your cuts, addnew ones, move and sew UV edges, or add/change pinned UVs betweeniterations.

When you are satisfied with your final unfolded result, use Polygons > Layoutas a final step to ensure the UVs are laid out as you require.

The following workflow tips can be useful in helping you achieve your desiredfinal unfolded result.

Related topics




■ Edit UVs > Unfold on page 123

UV unfolding workflow tips

Single vs. multiple meshes

While it is possible to unfold a complete UV mesh for one model in one piece,an alternate approach might be to cut the UV mesh into smaller sections andunfold portions of the mesh separately. With this strategy you can more easilycontrol regions of the unfold by pinning and so on. You’ll need to determinewhere you can safely cut the mesh, and later re-sew the UVs if required afterthe unfold operations are complete. Which approach you take will bedetermined by the complexity of the mesh and your individual productionrequirements.


Determining and selecting edge cut locations

The edge cuts should be located on the UV mesh in such a way that the UVmesh would lay flat if it were unfolded. Edge cuts are important because theyallow the UV texture coordinates to freely unfold with as little distortion aspossible during the Unfold operation.

The edge cuts should also be located in areas of the UV mesh where they willstay mostly unseen in the final rendered images. This reduces the possibilityof the viewer seeing the texturing artifacts that can result along texture edges.

You can quickly select a path of edges using the Select Shortest Edge Path Tool(Select > Select Shortest Edge Path Tool).

The Edge Loop tools can be useful for quickly inserting edges into the meshin locations that are not obvious to the viewer.

Quick Select sets

Whenever you need to make complex edge, vertex, or UV selections repeatedly,you can create selection sets for these components (called Quick Select sets)to easily select these components later on. To create Quick Select sets, selectthe components you want in the set and then select Create > Sets > QuickSelect Set. This can be particularly useful when you need to repeatedly selectUVs for pinning during the unfold operations.

Highlighting texture borders

It is critical to view and select border edges in both the scene view and theUV Texture Editor. Turn on the display of texture borders by selecting Display> Polygons > Texture Border Edges. This displays the UV borders on thepolygon mesh as thicker lines so you can see your progress as you cut the UVedges.

Pinning

Depending on where you initially cut the edges of the UV texture mesh, youcan pin specific locations or regions of the UV texture mesh to create temporaryanchor points to use with the Unfold feature. For example, with a polygonmesh of a quadruped, you can select the vertices along its spine beginning atthe tip of the nose and ending at the tip of its tail (assuming this has not beencut), then align these vertices to a vertical axis or horizontal axis within theUV Texture Editor. When you perform the next Unfold iteration, turn on thePin Selected UVs option in the Unfold UVs Options window so the selectedUVs remain anchored while the Unfold operation proceeds. The UVs will then


unfold in relation to the area you pinned. If you create QuickSets of the UVcomponents involved, your pinning operations will proceed more quickly.

Pinning is useful for ensuring areas don’t move during the unfold. It’s alsouseful when you have some regions unfolded to your satisfaction, and needto maintain those regions while performing additional unfold iterations. Whennecessary you can pin a shell’s border edges. In this way you can use theUnfold feature while the shell border is pinned to unfold the shells’ interiorUVs.

In general, you get better results when pinning extreme points on the meshand respecting the polygon object’s symmetry whenever possible.

When using the Smooth UV tool to unfold, any unselected UVs areautomatically pinned.

Constraining the unfold to either a horizontal or vertical direction

By default, the Unfold feature unfolds the UVs in all directions in anunrestricted manner. You can constrain the unfold process so the UVs areconstrained to unfold in either the vertical or horizontal direction as theyappear in the 2D view of the UV Texture Editor.

This can be useful when the appearance of the UVs is fine in one direction,but needs refinement in another.

When using the Smooth UV Tool, you can constrain the direction of theunfold operation by holding the Shift button while dragging the mouse.

When using the Unfold option, you can set the Unfold constraint to eitherVertical or Horizontal to constrain the direction of the unfold. The Unfoldconstraint setting also respects any pinning settings you may have set for theunfold operation.

Aligning UVs

Use Edit UVs > Align to snap UVs to match any vertical or horizontal linesthat would naturally occur on the texture.

Aligning UV edges that run down the axis of symmetry can be used to youradvantage. For example, the line of UVs that run down the spine of asymmetrical four-legged animal. You can select and align these UVs and thenpin them so they act as a benchmark for further unfold operations.


UV Lattice Tool

The UV Lattice Tool in the UV Texture Editor can be used to modify a regionof a UV shell before performing further Unfold operations.

Example: Lay out a UV shell using unfold andrelax

You can use the Smooth UV Tool to relax or unfold an entire UV shell intothe UV space. You can then use the same tool to fix small imperfections inthe shell.

The following workflow provides the following benefits:

■ It is easier to assign a texture to a square area.

■ Ensures the texture is spread evenly.

To map a shell to the UV space

1 Create a mapping for your object by selecting Create UVs > PlanarMapping from the Polygons menu set.

In this case, a planar projection from the front (the Z Axis) is appropriate.In other cases you must determine the best projection to start with.

2 Open the UV Texture Editor (Window > UV Texture Editor).

Example: Lay out a UV shell using unfold and relax | 73

3 In the perspective view, select a path of edges along the back of the headstarting at the top of the forehead and ending at the bottom of the neck.

4 In the UV Texture Editor, select Polygons > Cut UV Edges.

5 Select the central UV at the top of the forehead and in the UV Texture

Editor, select Polygons > Unfold > .

The Unfold Options window appears.

6 Turn on Pin UVs and Pin selected UVs.

7 Set the Unfold constraint to Horizontal.

8 Click Apply and Close.

The UV shell unfolds relative to the selected UV on the forehead so thatthe previously cut edges are spread out horizontally.


NOTE Rather than using the Unfold option, you can also use the SmoothUV Tool to unfold the entire UV shell. In this case, you would select all theUVs except for the one at the top of the forehead and then Shift + drag theUnfold icon to the right.

9 Use the Scale Tool to scale the UV shell into the 0,1 texture space.

10 Select the edges on one side of the mesh.

11 Select Polygons > Straighten UV Border.

The UV border straightens.

12 Repeat steps 10 and 11 for each side of the UV shell.


13 Turn on the Snap to grids option.

14 Select the Move Tool and move the border UVs to the edge of the 0,1texture space.

The Snap to grids option ensures that the UVs snap to the border precisely.


15 Select all the UVs.

16 Select Tool > Smooth UV Tool > .

The Smooth UV Options window appears.

17 Turn on Pin Borders.

This ensures that the UV border aren’t distorted.

18 Set Space to UV Space.

19 Click Apply and Close.

Two controls named Unfold and Relax appear.

20 Drag the Relax control to the right.

The entire UV shell, except for the borders, relaxes evenly.

With the Smooth UV Tool you can use your eye to judge how much the UVshell should relax. However, whether you use this method or the Relax option(Polygons > Relax), it is unlikely that the UV shell will be perfect.

If you turn on the Shaded UV Display , you can see small imperfectionsin your relaxed shell. For example, the UV shell around the eyes and cornersof the mouth for this model cause the shell to overlap itself.


You can use the Smooth UV Tool to smooth out these problem areas.

To smooth imperfections in a relaxed shell

1 Select Tool > Smooth UV Tool > .

The Smooth UV Options window appears.

2 Turn off Pin Borders and then select Apply and Close.

3 Select a set of UVs around the eye.

4 Drag the Unfold control to the right until the UV shell no longer overlapsitself.

5 Repeat for the mouth.


6 You can select smaller or larger sets of UVs and use the Smooth UV Toolin conjunction with the transformation tools to quickly clean up yourUV shell.

Flip or rotate UV shellsThe Flip and Rotate features let you easily change the orientation of UV shellswithin the UV Texture Editor. Flipping a UV shell is useful if you need tocorrect a UV shell that is reversed or reverse wound (see Display UV windingorder on page 55).

Flip or rotate UV shells | 79

To flip UVs on a texture shell

1 Select the faces you want to flip the texture on.

2 Select Edit UVs > Flip.

In the UV Texture Editor, you can select Polygons > Flip.

or

Select Edit UVs > Rotate.

3 Choose the direction to flip, and whether to flip within the boundingbox of the selection (local) or across the texture space axes (global).

4 Click Apply.

Related topics

■ Edit UVs > Flip on page 111

■ Edit UVs > Rotate on page 113

Copy UVs and color attributes betweenpolygons

You can copy UV, shader, and color per vertex attributes between faces ofdifferent polygon meshes using the Mesh > Clipboard Actions features. Theability to copy UV attributes between meshes is useful when a polygon meshhas been modified and you cannot further modify the UVs. It is also usefulfor copying attributes between meshes that have differing topologies.

You can only copy attributes between polygon faces that have similar vertexcounts. The copied UV attributes are placed in a separate shell.

To copy UVs, shaders, or color per vertex data between polygons

1 Select the polygon face whose attributes you want to copy and choose

Mesh > Clipboard Actions > Copy Attributes > .

2 In the Copy Clipboard Options window, set the attributes you want tocopy (UV, Shader, and Color) and click Apply and Close.

NOTE You can set the options so that one or more attributes get copied tothe clipboard.


3 Select the polygon face you want to copy the attributes to and chooseMesh > Clipboard Actions > Paste Attributes.

The previously copied attributes are pasted onto the selected face.

NOTE You can also clear the attributes contained on the clipboard bychoosing Mesh > Clipboard Actions > Clear Clipboard.

Related Topics

■ Make a hole in a polygon face

■ Mesh > Clipboard Actions > Copy Attributes

■ Mesh > Clipboard Actions > Paste Attributes

■ Mesh > Clipboard Actions > Clear Clipboard

Copy UVs and color attributes between polygons | 81

82

UV sets

Create UV setsThe quickest way to create UV sets is while you map UVs. When you map UVs,open the options window, turn on Create New UV Set, and type a name in theUV Set Name box. For example, if you create two planar mappings, one fromthe top and one from the side, type a new UV set name each time you map.

Alternatively, you can start with an empty UV set and then create UVs.

To create an empty UV set

1 Select the object, then select Create UVs > Create Empty UV Set > .

2 In the Create UV Set Name box, type the name of the empty set and clickCreate.

3 Select the new UV set (see Switch between UV sets on page 84).

4 Create UVs with one of the mapping operations or by copying.

Related topics


■ UV sets on page 11


■ Create UVs > Create Empty UV Set on page 107

4

83

Switch between UV setsYou can easily switch the UV sets that get applied to your polygon model.

To switch between UV sets


■ In the UV Texture Editor, select UV Sets > UVsetName.UVsetName indicates the list of UV sets.

■ In the scene view, press the right mouse button on a mesh and choose UVSets > UVsetName.UVsetName indicates the list of UV sets.

■ Select Create UVs > Set Current UV Set. In the window, type the name ofthe UV set you want.

Related topics




Duplicate, rename, or delete a UV setSelect the UV set you want to rename, copy from, or delete.

Do one of the following:

■ Select Create UVs > Copy UVs to UV SetThis copies the current UV set to a new UV set.

■ Select Create UVs > Rename Current UV SetType a new UV set name in the window that appears.

■ Select Create UVs > Delete Current UV Set

Related topics


84 | Chapter 4 UV sets


■ Create UVs > Copy UVs to UV Set on page 108

Assign a texture to a UV setYou assign textures to UV sets using the Relationship Editor.

Select Window > Relationship Editors > UV Linking > UV-Centric to open theRelationship Editor’s UV set editing view.

Do thisTo...

Click the UV Set in the left column, thenclick the texture in the right column so it’shighlighted.

To assign a texture to a UV set.

Click the UV Set in the left column, thenclick the texture in the right column so it’snot highlighted.

To remove a texture from a UV set.

From the Edit menu above the list of tex-tures, choose one of the following:

Temporarily keep textures from appearingin software renders.

■ Ignore Texture: hides the selectedtexture.

■ Use Texture When Rendering: uses theselected texture.

■ Isolate Texture: hides all textures butthe selected one.

■ Use All Textures When Rendering.7

Assign a texture to a UV set | 85

The Relationship Editor also provides easy access to several of the UV setediting operations in its Edit menu.

Related topics




Copy UVs from one UV set to anotherTo copy UVs from one existing UV set to another

1 In the UV Texture Editor, select the UVs you want to copy.

2 In the UV Texture Editor, open the Polygons > Copy UVs to UV Setsub-menu and choose a UV set.


Notes

■ When polygon UV sets are copied with history, the source UV set is linkedwith the destination. Any changes made to the source UV set by usingconstruction history, will influence the copied UV set. To avoid this issue,delete construction history after copying the UV set.

Related topics



Working with per-instance UV setsWhile you could always associate different instances of a particular shape withdifferent materials, you can now associate different UV sets with differentinstances. This is very useful when baking shadows on instances of an object(for example, lighting a game level), or creating instances of a single shapewith different textures (for example, a pile of boxes, some with holes indifferent locations, and so on).

When the UV sets are per-instance, the term UV set family refers to theassociated UV sets which apply to different instances. Within a given family,a single UV set may be applied to one or more instances.

To create a per-instance UV map

1 Select a shape.

2 Select Create UVs > Create Empty UV Set > .

You can choose to share this UV set (every instance has the UV set), PerInstance Shared (all selected instances share the new UV set), or PerInstance Unshared (all selected instances get a unique UV set).

3 Name your UV set as required.

4 Select another instance of the shape.

5 Right-click on the instance, select UV sets and make the per-instance UVset that you created the selected set.

Working with per-instance UV sets | 87

6 Select a UV mapping type under the Create UVs menu (such as Planar,Cylindrical or Spherical). Make sure that Create New UV Set is disabledin the mapping’s option window.

A new UV map is create for the selected instance that shares the nameof the current set.

7 Assign a shader to all instances of the mesh.

8 Right-click on an instance and select the UV Sets > UV Linking... Use theRelationship Editor to connect any of the per-instance sets to the colorof the shader.

Different (per-instance) UV mappings should now be displayed on yourinstanced objects when you render them or display them in the Scene viewwith Hardware texturing.

Example: Baking a single shadow map with per-instance UV sets

In the following example, we’ll bake shadows to a single map usingper-instance UV sets. At that point, we can delete lights in the scene. Thisworkflow is useful for creating texture maps on objects for game levels.

For more details about baking, see Lighting/shading > Batch Bake (mental ray)of the Shading guide.

In this simple scene, there is a long cylinder to cast shadows, a directionallight, a small plane with 16 x 16 subdivisions, and two additional instancesof the plane.

Setting up your scene

1 Create a long, skinny polygonal cylinder whose base is on the groundplane.


2 Create a small polygonal plane on the ground plane and from thepolyPlane node, set Subdivisions Width and Subdivisions Height to 16each.

3 Select the polygon plane and select Edit > Duplicate Special > .

4 Set Geometry Type to Instance and select Apply twice to create twoinstances of the small polygonal plane (the instances will appear overtopof the original).

5 Position the planes one after another like a sidewalk.

6 Create a directional light (Create > Lights > Directional Light) and positionit pointing slightly down and towards the cylinder and planes.

7 In the Attribute editor, change the Intensity of the light to 4.5.

8 Open the Shadows section and turn on Use Depth Map Shadows.

9 Change the shadow color to blue.

10 Render the scene using the mental ray renderer. Your render should looksomething like this:


You may need to adjust the direction of the light and re-render so that theshadow falls on each polygonal instance in a different location, as in the aboverender.

Now we can create UV sets per instance on the planes.

Creating per-instance UV sets

1 Select the three polygonal plane instances and in the Polygons menu set,

select Create UVs > Create Empty UV Set > .

2 In the Create UV Set Options dialog box, create a UV set named Sidewalkand select Per Instance Unshared. Then click Create.

3 Right-click on one of the polygonal plane instances and make Sidewalkthe selected UV set by selecting UV Sets > Sidewalk (n).

4 Select all the polygonal plane instances, and create UVs by selecting

Create UVs > Planar Mapping > and selecting:

■ Fit Projection to: Bounding Box

■ Project from: Y axis

Make sure that Create new UV Set is turned off.

5 Click Project.


You’ve now created a per-instances UV set whose UVs don’t overlap in UVspace. (You can use the UV Texture Editor to confirm this and move UVs ifnecessary.)

Now we’ll bake the shadows to a single UV map.

Baking to per-instance UV sets

1 Select the three polygonal plane instances.

2 In the Rendering menu set, select Lighting/shading > Batch Bake (mental

ray) > .

3 Set the following:

■ Objects to bake: Selected

■ Bake to: Texture

■ Bake shadows: on

■ Use bake set override: on

■ Color mode: Only light

■ Bake to one map: on

4 Click Convert and Close.

While the shadows are baked, you now have to connect the bake set tothe UV map.

5 Right-click one of the instances and select UV Sets > UV Linking.

6 In the Relationship editor, link the Sidewalk(0) map to baked_inBake1.


The shadows are baked and properly linked. You can see this in the Sceneview if you’re in Shaded mode (Hotkey: 6) or High-Quality renderingmode.

7 At this point, you can delete the light in your scene since its shadowshave been baked to the UV textures on your polygonal instances.

Deleting per-instance UV sets

Deleting UV sets works slightly differently now that there can be UV setfamilies shared between instances.

For example, a per-instance set family named myMap has two child sets. Oneis applied to multiple instances (instances a, b, and c) and one is applied onlyto instance d. It is the current UV set. If you select instance d, and select DeleteCurrent UV Set, only the map on instance d is deleted. (The other UV map isused by unselected instances and is not deleted.)

If you then select instance a and select Delete Current UV Set, the UV set isunshared from instance a, but still exists on instances b and c. To delete it


altogether, you can then select instances b and c and select Delete CurrentUV Set.

Limitations

Per-instance UV sets do not support color sets or paint effects.

Edit NURBS UVsMaya provides limited support for editing the UV texture coordinates of NURBSsurfaces within the UV Texture Editor. Edit NURBS UV mode is useful for gamesdevelopers who use NURBS surface types in games applications and requirethe ability to modify an explicit UV set for subsequent export to a gamesengine. This feature does not provide support for editing NURBS UVs for usewith texture mapping or image rendering features within Maya.

Edit NURBS UV mode creates an explicit and unique UV set for the NURBSsurface. The user switches between the implicit UVs for the NURBS surfaceand the explicitly created UV set. It is then possible to edit the explicit NURBSUVs on a limited basis.

It is recommended that you create and edit the explicit NURBS UVs only whenall editing and modification of the NURBS surface model is complete. See theNotes on page 94 and Edit NURBS UVs Limitations on page 94 below.

For more information on the MELTM commands and flags that provide thisfunctionality, see the nurbsUVSet, nurbsEditUV commands in the MEL guide.

To edit UVs for a NURBS surface in the UV Texture Editor

1 In the scene view, select the NURBS surface that you want to create andedit explicit UVs for texturing.

2 Ensure that the construction history for the NURBS surface is deleted byselecting Edit > Delete All by Type > History.

Deleting construction history prior to making any UV edits ensures thatsubsequent updates to the node dependency graph do not remove theUV edits you make to the explicit NURBS UV set. Do this only when youare sure you will no longer be required to edit the model (Save a copy ofthe model that contains construction history in case you need to revertback for any reason).

3 Turn off construction history while you work on the NURBS UVs usingthe Construction History on/off icon on the Status Line.

Edit NURBS UVs | 93

4 Open the UV Texture Editor by selecting Edit UVs > UV Texture Editor.

The NURBS UVs that are implicitly created with the NURBS surface appearin the 2D view of the UV Texture Editor.

5 In the UV Texture Editor, right + click in the 2D view, and select EditNURBS UV mode from the marking menu that appears.

A UV set for the NURBS surface is explicitly created and displayed in the2D view of the UV Texture Editor. The NURBS UV set created is based onthe topology of the NURBS surface.

6 Change the selection method to UVs by doing one of the following:

■ Right + click in the scene view and select Surface UV from the markingmenu.

■ Right + click in the 2D view of the UV Texture Editor, and select UVfrom the marking menu.

7 Select the UVs you want to modify in either the scene view or in the 2Dview of the UV Texture Editor.

8 Using the transformation tools from the Toolbox (Move Tool, RotateTool, or Scale Tool), edit the position of the NURBS UVs in the UV TextureEditor.

Notes

■ Deleting the construction history on the NURBS surface is a requirementprior to creating and editing the explicit NURBS UVs. This ensures thatupdates to the dependency graph do not overwrite UV edits.

■ Modifying the NURBS surface topology in any way (that is, inserting anisoparm on the NURBS surface) after the explicit UV set has been modifiedwill overwrite the unique NURBS UV set. The explicit NURBS UV set willbe updated to take into account the changes to the topology, but any UVmodifications will be lost.

Edit NURBS UVs Limitations

■ The explicit UV set created with this feature is unique for each NURBSsurface. That is, unlike polygon and subdivision surface types, it is notpossible to create multiple NURBS UV sets for a given NURBS surface.


■ The Maya renderers (software, hardware, mental ray for Maya, and so on)do not support explicit NURBS UVs. They are only capable of renderingthe implicit UVs for NURBS.

■ Construction history is not supported. That is, a user should plan theirtexturing workflow to occur after all edits and modifications to the modelare complete. Changing the topology of the model after the NURBS UVset has been edited will overwrite the UV edits whenever the nodedependency graph updates.

■ UV modification is limited to UV selection and transformation only (thatis, move, rotate, and scale). It is not possible to select and modify theexplicit NURBS UVs by patch or isoparm. The polygon and subdivisionsurface UV modification features do not work with the explicit NURBSUVs.

■ UV sharing is not supported. With explicit NURBS UVs a UV texturecoordinate exists for each patch corner on the surface. A bounding boxselection can be used to move interior NURBS UVs simultaneously.

Edit NURBS UVs | 95

96

UVs menu reference

Create UVs

Create UVs > Planar Mapping

Maps UV texture coordinates onto the selected surface mesh by projecting themalong one direction from an imaginary plane.

Related topics


Create UVs > Planar Mapping >

Fit projection to:By default, the projection manipulator is automatically positioned based onone of two settings:

Best plane If you want to map UVs for a portion of the object’s faces, you canselect Best plane and the projection manipulator snaps to an angle and rotationaimed directly at the selected faces.

Bounding box This option works best when you are mapping UVs to all ormost of an object’s faces. It snaps the projection manipulator to fit within theobject’s bounding box. With this option on, you must choose one of the Projectfrom directions to establish the orientation of the projection manipulator.

Project from Choose an axis (X, Y, Z) so that the projection manipulator isaimed at the majority of the object’s faces. For example, a turtle model sitting

5

97

on the grid would have most of its faces pointing along the Y axis, while ahorse model standing on the grid would have most of its faces pointing alongthe X or Z axis.

Choose the Camera option if most of the model’s faces point somewhere thatis not directly along the X, Y, or Z axis. This option positions the projectionmanipulator based on the current active view.

Keep image width/height ratio Turn this option on to retain the width toheight ratio of the image so that the image does not distort. Turn it off so thatthe mapped UVs fill the 0 to 1 coordinates in the UV Texture Editor.

Insert projection before deformers The Insert projection before deformersoption is relevant when the polygonal object has a deformation applied to it.If the option is turned off and the deformation is animated, the textureplacement is affected by the change in vertex positions. This leads to“swimming” textures.

Turning this option on applies the texture placement to the polygonal objectbefore the deformation is applied to it. That is, the texture placementdependency graph node is inserted before the deformer dependency graphnodes and the texture “sticks” to the geometry even after the deformation.

Create new UV set Turn this option on to create a new UV set and place theUVs created by the projection in that set. Type the name of your UV set inthe UV Set name box.

Manually adjusting the projection manipulator

You can use the manipulator handles to interactively adjust the UV map thatgets projected or enter values to change the Projection Center, Rotation andScale using either the Channel Box or the Attribute Editor. These valuescorrespond to the manipulator handles that display when you map yourtexture onto the polygon.

Projection Center The projection center defines the point of origin in the X,Y, or Z axis from where you can project a texture map. By default, this is thecenter of the selected faces in the X, Y, or Z axis.

Rotate Type a value to rotate the projection in the 3D view around the X, Y,or Z axis which subsequently rotates the texture.

Projection Width Sets the width (U) of the projection relative to the 3Dprojection axis.

Projection Height Sets the height (V) of the projection relative to the 3Dprojection axis.

98 | Chapter 5 UVs menu reference

Image Center This value represents the center of the projected UVs. Changingthis value translates the center accordingly.

Rotation Angle This value changes the angle at which UVs are rotated in the2D window. Drag the slider or enter a value to rotate the image.

Image Scale This value represents the width (U) or the height (V) of the 2Dmap relative to the 2D center point.

Create UVs > Cylindrical Mapping

Maps UV texture coordinates onto the selected objects by projecting theminward from an imaginary cylinder.

Related topics


Create UVs > Cylindrical Mapping >

Insert projection before deformers This option is turned on by default. TheInsert projection before deformers option is relevant when the polygonalobject has a deformation applied to it. If the option is turned off and thedeformation is animated, the texture placement is affected by the change invertex positions. This leads to “swimming” textures.

Turning this option on applies the texture placement to the polygonal objectbefore the deformation is applied to it. Basically, the texture placementdependency graph node is inserted before the deformer dependency graphnodes and the texture “sticks” to the geometry even after the deformation.



You can use the manipulator handles to interactively adjust the UV map thatgets projected or enter values to change the Projection Center, Rotation andSweep using either the Channel Box or the Attribute Editor. These valuescorrespond to the manipulator handles that display when you map yourtexture onto the polygon.

Create UVs > Cylindrical Mapping | 99



Horizontal Sweep Use the slider or type a value to scale the projection aroundthe polygonal object in the horizontal direction. This value corresponds tothe Projection Scale Aperture handles on the manipulator. For instance, pullthe Projection Scale Aperture handles all the way around the object until theymeet. This is equivalent to entering 360 in the box.

Vertical Sweep Use the slider or type a value to scale the projection aroundthe polygonal object in the vertical direction. This value corresponds to theProjection Scale Aperture handles on the manipulator. For instance, pull theProjection Scale Aperture handles all the way around the object until theymeet. This is equivalent to entering 360 in the box.

Projection Height Scaling a projection enlarges or reduces the height (V) ofa map relative to the 3D projection axis.




Create UVs > Spherical Mapping

Maps UVs onto the selected objects by projecting them inward from animaginary sphere.

Related topics


Create UVs > Spherical Mapping >

Insert projection before deformers This option is turned on by default. TheInsert projection before deformers option is relevant when the polygonal


object has deformation applied to it. If the option is turned off and thedeformation is animated, the texture placement is affected by the change invertex positions. This leads to “swimming” textures.




You can use the manipulator handles to interactively adjust the UV map thatgets projected or enter values to change the Projection Center, Rotation andSweep using either the Channel Box or the Attribute Editor. These valuescorrespond to the manipulator handles that display when you map yourtexture onto the polygon.



Horizontal Sweep Use the slider or type a value to scale the projectionhorizontally around the polygonal object. This value corresponds to theProjection Scale Aperture handles on the manipulator. For instance, pull theProjection Scale Aperture handles all the way around the object until theymeet. This is equivalent to entering 360 in the box.

Vertical Sweep Use the slider or type a value to scale the projection verticallyaround the polygonal object. This value corresponds to the Projection ScaleAperture handles on the manipulator. For instance, pull the Projection ScaleAperture handles all the way around the object until they meet. This isequivalent to entering 360 in the box.



Create UVs > Spherical Mapping | 101


Create UVs > Automatic Mapping

Projects UV texture coordinates onto the selected object from multiple anglessimultaneously. An Automatic Mapping Projection Manipulator is displayedaround the selected object to facilitate more accurate UV projection.

Related topics


Create UVs > Automatic Mapping >

Planes Selects the number of planes for the Automatic Mapping projection.You can choose a projection mapping based on shapes with 3, 4, 5, 6, 8 or 12planes. The more planes used, the less distortion occurs and the more UVshells created in the UV Texture Editor. The number of planes that appear onthe Automatic Mapping Projection manipulator directly relates to the numberof planes set in this option.

Optimize for:Sets the optimization type for the automatic projection.

Less distortion Projects all planes equally. While this method provides thebest projection for any face, you may end up with more shells. It is particularlyuseful if you have a symmetrical model and you want the shells of theprojection to be symmetrical.

Fewer pieces Projects each plane until the projection encounters a projectionangle that is not ideal. This can result in larger shells, and fewer of them. Thisis the default.


NOTE In some cases, setting the Optimize for setting to Less Distortion can producea slightly different UV layout when you open the same file on another operatingsystem. If this happens you can either:

■ Set Optimize for to Fewer pieces.

■ Keep the Less Distortion setting but delete history on the object (Edit >Delete by Type > History). This action assigns UVs directly to the surface.

Insert projection before deformers The Insert projection before deformersoption is relevant when the polygonal object has a deformation applied to it.If the option is turned off and the deformation is animated, the textureplacement is affected by the change in vertex positions. This leads to“swimming” textures.


Load projectionLets you specify a custom polygon object to be the projection object forautomatic mapping. You must initially create the polygon object in objectspace (X, Y, Z). The Load Projection object must exist in the current scene.The projection object can form a cage around the object or be comprised ofseparate faces that intersect each other at its center. The faces of the projectionobject must have UV texture coordinates. It is recommended that you useseparated faces. You can separate the faces for a polygon primitive using theMesh > Extractfeature. NURBS and subdivision surfaces are not valid surfacetypes for use with Load Projection. The maximum number of polygon facesthat can be specified for a projection object is 31.

You can translate any face from the Load Projection object along its normalwith no affect on the resulting projection. However, scaling or rotating anyface from the Load Projection object affects the resulting orientation and scaleof the final UV projection. Changing the UV texture coordinates on theprojection object also affects the resulting UV projection mapping that occurs.The Automatic Mapping projection manipulator updates to reflect the changein orientation whenever this occurs.

Projection object Identifies the currently loaded projection object in thescene. You specify the projection object by typing the name of the projectionobject in this field. Alternatively, the name of the projection object will appearin this field when the desired object in the scene is selected and the LoadSelected button is selected.

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Load selected Loads polygon faces that are currently selected in the scene asthe specified projection object. The specified faces are used to update theautomatic projection manipulator. While the maximum number of polygonfaces that can be specified for a projection object is 31, the recommendedrange is between 3 and 8.

Project both directions When Project both directions is off (default), Loadprojection projects UVs on polygon objects whose normals point in roughlythe same direction as the projecting plane of the Load Projection object. WhenProject both directions is turned on, the alignment of normals on both sidesof the projection faces determines which objects will receive a projection froma particular projection plane. That is, the normals are projected outwards fromboth sides of the Load Projection object and the surfaces whose normals alignare evaluated accordingly.

Shell layoutSets where the laid out UV shells will lie in UV texture space.

Overlap Overlaps the resulting projection within the 0 to 1 UV texture spacein the UV Texture Editor. Overlap is useful when the UV texture shells needto share the same texture. When the Load Projection option is turned on,Overlap becomes the default layout.

Along U Positions the shells along the U axis.

Into Square Positions the shells within the 0 to 1 texture space. This is thedefault.

Tile Separates the resulting UV projections so they reside in a separate 0 to 1UV space. Tile is useful when you anticipate additional editing or manipulationfor the UV projections and need them to remain separated.

Scale modeSets how the UV shells will be scaled within UV texture space.

None Performs no scaling.


Uniform Scales the shells to fit the 0 to 1 texture space without changing theaspect ratio. This is the default.

Stretch to Square Stretches the shells to fit the 0 to 1 texture space. The shellsmay become distorted.

Shell stackingDetermines how the UV shells get stacked in relation to each other when laidout in the UV Texture Editor.

Bounding Box Creates a rectangular bounding box around each UV shell,then stacks the shells based on the borders of the bounding boxes. The UVshells will have more space between them when this option is set.

Shape Stacks the UV shells based on the boundaries of each individual shell.The UV shells can be more tightly arranged to fit into any available spaceswhen this option is set.

Spacing presets Maya puts a bounding box around each piece and lays outthe shells so that the bounding boxes are very close together. If the shells endup positioned exactly next to each other, two UVs on different shells can sharethe same pixel and when painting with the 3D Paint Tool, overscanning canalso cause the paint to spill onto the adjacent shell.

Create UVs > Automatic Mapping | 105

To avoid this situation, ensure that there is at least a pixel between thebounding boxes by selecting a spacing preset from this menu. Select a presetthat corresponds to your texture map size. If you don’t know the size, selecta smaller map, which will result in a larger spacing between adjacent shellsin UV space. (The smaller your map in pixels, the bigger the UV spacing mustbe between bounding boxes.)

Select Custom to set the size of the space as a percentage of the map size (inthe Percentage Space box).

Percentage space If you select Custom beside Spacing Presets, enter the sizeof the space between bounding boxes as a percentage of the map size.

Create new UV set Turn this option on to create a new UV set and place thenewly created UVs in that set. Type the name of the UV set in the UV SetName box.

Create UVs > Create UVs Based On Camera

Creates UV texture coordinates for the selected object based on the currentcamera view as a planar projection. That is, the camera view becomes theplane of projection.

Create UVs > Create UVs Based On Camera >

Create new UV set Turn this option on to create a new UV set and place thenewly created UVs in that set. Type the name of the UV set in the UV SetName box.

Related topics




Create UVs > Best Plane Texturing Tool

Assigns UVs to the faces you select based on a plane computed from verticesyou specify.

NOTE It is important that you either select all faces before invoking the tool, orset the selection mask explicitly to Polygon. Otherwise selection problems canoccur. Use the Best Plane Texturing Tool on on shape at a time. You can still usevertices from a different shape to define the plane.

Related topics


Create UVs > Assign Shader to Each Projection

When Assign Shader to Each Projection is turned on, a shader with acheckerboard texture is assigned to the selected mesh as you project UV texturecoordinates. This aids in determining the alignment of the UVs by providinga known visual reference. The default setting is off.

Related topics


Create UVs > Create Empty UV Set

Creates a new, empty UV set on the current object. You can then create theUVs in the set using one of the mapping/projection methods. This feature isalso available for use from the Polygons menu in the UV Texture Editor.

Related topics




Create UVs > Best Plane Texturing Tool | 107

Create UVs > Create Empty UV Set >

Create UV Set name Type a name for the new UV set in the text field.

UV Set Sharing You can choose to share this UV set (every instance has theUV set), Per Instance Shared (all selected instances share the new UV set), orPer Instance Unshared (all selected instances get a unique UV set).

Create UVs > Copy UVs to UV Set

Creates a new UV set based on an existing UV layout or transfers a UV layoutfrom one set to another. This feature is also available for use from the Polygonsmenu in the UV Texture Editor.

Related topics




Create UVs > Set Current UV Set

Lets you specify which UV set you want to use for a particular polygon mesh.You specify which set you want by typing the name of the UV set in the textfield that appears. This feature is also available for use from the Polygons menuin the UV Texture Editor.

Create UVs > Set Current UV Set...

UV set name Type the name of the UV set you want to switch to in this textfield.

Related topics





Create UVs > Rename Current UV Set

Lets you rename the currently selected UV set. This feature is also availablefor use from the Polygons menu in the UV Texture Editor.

Create UVs > Rename Current UV Set...

New UV set name Type the name of the UV set you want to switch to in thistext field.

Related topics



Create UVs > Delete Current UV Set

Deletes the currently selected UV set. This feature is also available for use fromthe Polygons menu in the UV Texture Editor.

Related topics



Create UVs > UV Set Editor

The UV Set Editor lets you create and edit UV sets for multiple polygon meshessimultaneously. For more information see UV Set Editor on page 160.

Create UVs > Per Instance Sharing

You can select shared instances, share instances, or make the selected instancecurent.

Create UVs > Rename Current UV Set | 109

Edit UVs

Edit UVs > Normalize

Scales the UVs of the selected faces to within the 0 to 1 range of the UV texturespace.

Related topics

■ Move, rotate, and scale UVs on page 35

■ Edit UVs > Unitize on page 111

Edit UVs > Normalize >

Use the following options as required to Normalize the UV texture coordinates.

Collectively Select Collectively to normalize the UVs for all selected facescollectively. That means the texture coordinates for all selected faces are“collectively” fit to the 0 to 1 texture space. This is the default.

Each face separately Select Each face separately to normalize the UVs foreach selected face separately. That means the texture coordinates for eachselected face are fit to a boundary of 0 to 1.


Preserve aspect ratio Turn this option on to scale the UVs uniformly alongU and V.

Turn this option off (the default setting) to stretch the texture to fit by scalingU and V non-uniformly.

When you normalize texture coordinates, you scale the UVs of the selectedfaces. If Preserve Aspect Ratio is on, the scaling is guaranteed to be uniformon both the U and V axes. If turned off, the scaling will be different for the Uand V axes.

Edit UVs > Unitize

Repositions the UVs of the selected faces on the boundary of the 0 to 1 UVtexture space as they appear in the UV Texture Editor.

Related topics


■ Layout UV shells on page 58

Edit UVs > Unitize >

Create new UV set Turn this option on to automatically create a new UV seton the object to hold the unitized UVs. Enter a name for the new UV set inthe UV Set name box.

Edit UVs > Flip

Flips the positions of the selected UV shells either horizontally or vertically.

Edit UVs > Unitize | 111

Related topics


Edit UVs > Flip >

Direction Set the direction to flip the UVs of the selected shells: Horizontalor Vertical. The default is Horizontal.

Coordinate Set Global as required to flip the UV shells in global UV space inthe 0 to 1 texture space axis. Select Local to flip the UVs within the boundingbox of the selected shells. The default is Local.


Edit UVs > Rotate

Rotates the positions of the selected UVs.

Related topics


Edit UVs > Rotate | 113

Edit UVs > Rotate >

Rotation angle The angle by which the UVs are rotated. The UVs rotate abouttheir average center.

Edit UVs > Grid

Repositions any currently selected UV to its nearest grid intersection in UVtexture space.

Related topics


Edit UVs > Grid >

Map size presets Sets the Grid U and Grid V options to common square texturesizes.

Change the Grid U and Grid V sliders or enter values to use a different ornon-square size.

Grid U The number of grid lines horizontally (in the U dimension of texturespace).

Grid V The number of grid lines vertically (in the V dimension of texturespace).

Move UVs toThe options available are:

Pixel border Snaps UVs to the nearest grid intersection.

Pixel center Snaps UVs to the nearest midpoint between grid lines.

Edit UVs > Align

Repositions any selected UVs so they are aligned to a particular U or V valuebased on the options setting.


Related topics


Edit UVs > Align >

Align selected UVs to Sets whether the selected UVs are aligned to the left(minimum U), right (maximum U), bottom (minimum V), or top (maximumV).

Edit UVs > Warp Image

Modifies a texture image by comparing two UV sets on a single polygonalmesh and produces a new bitmap image. To use this feature you must specifya source image, as well as a source and destination UV set for the model fromwhich the UVs will be referenced for the image manipulation. Warp Imageproduces a new target image as the result.

Related topics

■ Copy UVs and color attributes between polygons on page 80

Edit UVs > Warp Image >

These are the descriptions for the options in the Warp Image Options window.

Source image name Specifies the name and file path of the image that isinput for warp modifications.

New image name Specifies the name and file path of the final image that isoutput from the warp calculations.

Background modeBackground mode determines how colors are interpolated at the texture edges.When warping an image, occasionally some of the pixels along texture edgesare missed. As a result, areas of the polygon mesh may not be properly coveredas the background color shows through. The Background mode andBackground color options helps manage this situation by allowing you to

Edit UVs > Warp Image | 115

specify a color to apply to the background. You can specify a fixed color thatcontrasts with the original source image so you can easily determine thelocations of the pixel gaps or attempt to hide the gap using a color that isdetermined from the texture map.

Automatic Extrapolates colors from the pixels on the related texture map toautomatically minimize colors showing through. The results depend on thetexture map.

Fixed color Uses the color specified in the Background Color setting.

Background color Specifies the color used for the Background mode. Thiscan also be useful if you want to import the file texture into an image editingsoftware application, and want a special key (color) to select the backgroundfor processing.

File format Specifies the image file format for the new image that is createdas a result of the Warp Image modifications. File formats include PIX, ALS,IFF, TIFF, CINEON, EPS, GIF, JPG, YUV, RLA, SGI, TGA, and BMP.

Source UV set Specifies the polygon UV set that is referenced for warpmodification.

Destination UV set Specifies the polygon UV set that is used as a target whendetermining where to modify the final warped image.

X resolution Specifies the X-axis resolution for the resulting warped imagein pixels. The default X resolution is 256.

Y resolution Specifies the Y-axis resolution for the resulting warped image inpixels. The default Y resolution is 256.

Overwrite existing file When Overwrite Existing File is turned on (default),the target image overwrites a file of the same name if it exists in that location.When Overwrite Existing File is turned off and a file exists of the same nameas specified in the New Image Name option, the Warp Image operation willquit without producing an image.

Bilinear filtering When Bilinear Filtering is turned on (default), the targetimage is anti-aliased by averaging the colors of adjacent pixels. When BilinearFiltering is used the resulting new image may be softer with less contrast as aresult of the anti-aliasing that occurs. When Bilinear Filtering is off, a pointsampling method for anti-aliasing is used that produces a sharper image withmore contrast. Additional post-processing of the image may be necessary.

Include alpha Specifies whether the alpha channel is incorporated into theWarp Image calculations. When the option is turned off the Alpha channelinformation is discarded.


Tiled When the Tiled option is turned on (default) the source image is repeatedin U and V directions. For example, the UVs that extend beyond the UV rangewrap to the other side. When Tiled is turned off, pixels that reside outside ofthe 0 to 1 UV range are ignored by the Warp Image feature.

NOTE Tiling a warped image has implications if the wrapped UVs overlap withother UVs as a result. The Warp Image feature will have trouble determining wherethe pixel should be assigned in the areas of overlap and unpredictable results willoccur in the final image. For that reason, UVs should be laid out so they do nottile. If they must tile, they should tile without overlapping.

Edit UVs > Map UV Border

Repositions border UVs on a selected UV shell to a square or circle within the0 to 1 range of the UV texture space.

You can move the UVs on the border of a UV shell out to the edges of the 0to 1 texture space (square), or to a circle inscribed within the 0 to 1 range.You can optionally scale the edges proportionally as you move the borderUVs.

Map UV Border is useful for untangling borders before you use Relax UVs tountangle interior UVs.

Related topics


■ Edit UVs > Straighten UV Border on page 120


Edit UVs > Map UV Border >

Border target shapeSelect the shape type that you want to map the UV border to (Square or Circle).

Square The Square option maps the border UVs along the axes of the 0 to +1texture range so the UV shell borders appear in a square shape. Square makesbest use of texture space but can result in faces having zero or very little texturespace around the UV border.

Edit UVs > Map UV Border | 117

Circle The Circle option maps the border UVs about a circle that is inscribedwithin the 0 to +1 region. Circle uses texture space less efficiently because ofthe unused corner regions.

Automatic Turn on Automatic to map the UV border automatically in a shapethat approximates the best use the texture space while maintaining theworld-space relationships between edges.

Preserve original shape Determines how closely the border mapping willmatch the selected Border Target Shape. Use the slider or enter a value between0 and 1 to control the blend of the existing UV border with the specifiedBorder Target Shape. A value of 0 produces a UV border mapping that is closestto the specified target shape (Square or Circle). A value of 1 produces a borderthat closely represents the world-space relationships between edges, but canresult in concave areas along the border—these will produce overlappinginterior UVs once relaxed.


NOTE Map UV Border may not be able to find a unique border with non-manifoldgeometry.

If you have a piece of non-manifold geometry, any particular UV may be inmore than one border/shell, so it does not uniquely determine a flat piece ofmesh to relax. Map UV Border will find a boundary and map it, but you can'tcontrol which one it will get.

To work around this you can cut the UVs along the non-manifold edges tomake sure that they're “flat”, or use Cleanup to eliminate the non-manifoldareas first.

Edit UVs > Map UV Border | 119

Edit UVs > Straighten UV Border

Untangles the border of the currently selected UV shell, such as an edge thatloops around itself. Straighten UV Border provides more control than the MapUV Border operation in these circumstances.

Related topics


■ Edit UVs > Map UV Border on page 117

Edit UVs > Straighten UV Border >

Curvature Pushes the selected border area outward or inward by the specifiedamount. A value of zero forces the edge to be straight. Each Curvature unit is.01 on the UV coordinate scale.

Maya curves the border outward or inward depending on whether the valueis positive or negative. However, you cannot tell in advance whether to usepositive or negative. With the polyStraightenUVBorder node opened in theChannel Box or Attribute Editor, try positive and negative values and checkthe results in the UV Texture Editor.

Preserve length ratio Controls the size of UV texture edges when straightened.Set to one, Maya preserves the original edge lengths. Set to zero, Maya averagesthe lengths. Values between zero and one change the length proportionally.

Blend original shape Affects the shape of the straightened border by blendingit with the original border shape. You can use this setting to constrain theeffect of the above two settings. Set to one, Maya keeps the original shape andoverrides the other settings. Set to zero, Maya does not consider the originalshape when straightening. Values between zero and one proportionally blendthe original shape with the curvature created by the other settings.

Fill gaps in selectionThe Fill gaps in selection options helps you straighten UVs that are missingfrom your selection because they are difficult to select.

UV gap tolerance The UV Gap Tolerance setting is the threshold of whenMaya selects and straightens the unselected UVs. For example, if there arethree unselected UVs in the middle of two selected UVs, UV Gap Tolerancemust be 3 or higher in order for Maya to select and straighten the middle UVs.The following illustration shows an example.


Edit UVs > Relax

Automatically untangles and evens out the spacing between UV texturecoordinates. You can choose to pin the border UVs so they remain in the sameposition while relaxing other UVs, or pin the selected or unselected UVs whilerelaxing any other UVs.

Related topics


Edit UVs > Relax >

Pinning

Use the following options to relax only selected portions of the UV shell.

Pin UV border Turn this option on to maintain the position of the borderUVs. This is the default.

Edit UVs > Relax | 121

Pin UVsSelet which UVs to pin.

Pin selected UVs Turn this option on to maintain the position of selectedUVs. For example, if you want more texture space for an area on a face withvery dense UVs, you could select these UVs, scale them up, pin them, thenrelax the rest of the UVs to eliminate any overlapping you may have introducedduring the scale.

Pin unselected UVs Turn this option on to maintain the position of theunselected UVs. This option is useful for relaxing only the selected UVs.

Edge weightsSelect how the UV relax operation affects edges.

Uniform Attempts to make all of the edges the same length. This is the default.


World space Attempts to retain the original world-space angles (subject tothe restrictions of the pinned border).

Maximum iterations Enter the number of relaxation iterations that will beperformed on the UVs—ideal UV relaxation is subjective and iterative.

Edit UVs > Unfold

The Unfold feature lets you unwrap the UV mesh for a polygonal object whiletrying to ensure that the UVs do not overlap. Unfolding UVs helps to minimizethe distortion of texture maps on organic polygon meshes by optimizing theposition of the UV coordinates so they more closely reflect the original polygonmesh.

For example, if the initial shape of the UVs results in a distorted texture patternon the surface mesh, you can use the Unfold feature to minimize the distortionbecause it attempts to maintain the UV’s relationship relative to the originalsurface mesh.

Related topics

■ Unfold a UV mesh on page 65

■ UV unfolding workflow tips on page 70

Edit UVs > Unfold >

These are descriptions for the options in the Unfold Options window.

Weight solver towards A bias setting that determines the weighting betweentwo unfold solver types: local and global.

When Weight Solver towards is set to 0 (default) a local solver is used for theunfolding calculations.

When the Weight solver towards is set to 1 a global solver is used for theunfolding calculations.

When the Weight solver towards is set anywhere between 0 and 1, theunfolding results are based on the combined solver calculations.

A Weight Solver towards setting of 0 is recommended for the majority ofunfolding operations and provides the quickest results.

Some polygon configurations can cause the Unfold feature to produce anundesired tapering effect on the unwrapped result. For example, the tapered

Edit UVs > Unfold | 123

shape from the thigh towards the ankle on a character’s pant leg may resultin a more exaggerated tapering as a result of how the local solver works whenit unfolds the UVs. When this occurs, the results can usually be improved byperforming additional unfold operations with the Weight solver towardssetting set to a value above 0 so that the global solver is taken into account.The unfold operation will take substantially longer, but the tapering effectwill be reduced. Once the scale is more uniform, you can carefully pin UVsto control areas that were previously at different scales to ensure they don’trevert back. Once the UVs are pinned, you can perform subsequent unfoldoperations with the Weight solver towards setting at 0.

For an example of how this works see Solver weighting example on page 126.

Optimize to originalSpecifies which polygon comparison method is used for the unfoldingoperation. This setting is only available when the Weight solver towards settingis greater than 0 and can be biased towards two comparison methods:

Face area Compares polygons by comparing the area of individual UVs to theoriginal faces of the polygon mesh.

Edge length Uses a method that compares the length of the edges of the UVsto the face edges of the original polygons.

When the Face area/Edge length bias setting is set to 0.5 (the default) bothmethods of comparison have equal weighting in determining the final result.In general, this is a good starting point for the majority of unfold calculations.

Polygon meshes with high areas of curvature can have better unfold resultswhen the bias is set towards Face area. This setting minimizes the buckling ofthe texture map in the areas of curvature. However, if the bias setting is setfully towards Face area, a shearing effect on the texture can occur as a resultof the calculations attempting to work within the constraints specified by theFace area bias.

Pinning

Use the following options to unfold only selected portions of the UV shell.

Pin UV border Maintains the position of the UVs along the poly shell’s borderedge during the unfold operation. Use this option when you want the shell’sborder edge to be unaffected by the unfold operation.

Pin UVsLets you perform the Unfold operation but pin specific UV combinations.

Pin selected UVs Maintains the position of only the selected UVs during theunfold operation.


By default, Unfold repositions all of the selected UVs during the unfoldoperation and the unselected UVs remain pinned. This option reverses thatdefault behavior. This option can be useful when specific UVs are already ina desired pattern when unfolded and you need some of the UVs to remainunaffected by subsequent unfold operations.

Pin unselected UVs Maintains the position of only the unselected UVs duringthe unfold operation. This is the default setting.

When this option is on, Unfold repositions all of the selected UVs during theunfold operation and the unselected UVs remain pinned.

Unfold constraintSpecifies how the unfolding of the UVs will be constrained as they areunfolded.

None The UVs will unfold freely in any direction during the unfold operation.

Vertical The UVs will be constrained in the vertical direction as they appearin the UV Texture Editor.

Horizontal The UVs will be constrained in the horizontal direction as theyappear in the UV Texture Editor.

Maximum iterations Specifies the maximum number of repeated calculationsallowed for the unfold solver when calculating the final unfolded result if theStopping threshold value has not been reached. When this maximum occurs,the unfold calculations will stop.

TIP You can stop the unfold calculations at any time by pressing Esc.

If the calculations appear to stop prematurely, it simply means that theStopping threshold has been reached. The default is 5000. Setting theMaximum iterations higher than 5000 causes the Unfold feature to calculatefurther towards the Stopping threshold and lengthens the time for the unfoldcalculation.

If the Weight solver towards setting is any value above 0, you may wish toinitially set Maximum iterations to a smaller value such as 50 for your initialunfold iteration.

Stopping threshold Specifies a mathematical threshold to stop the unfoldcalculations. The value is based on an internally computed relative percentageof overall improvement when comparing the angles, distances, and areasbetween the original polygon mesh and the unfolded result. The unfoldcalculations will progress until this percentage threshold is reached or untilthe maximum number of iterations specified by the Maximum iterationssetting is reached.


Setting the value smaller than 0.001 will result in longer times when unfolding.If time is not of concern, you can also set the Stopping threshold to 0 andallow the Unfold feature to calculate the best result.

Rescale Resizes each final unfolded UV shell to match the Scale Factor oncethe unfold calculations are complete. It accomplishes this by first determiningthe surface area of the polygon mesh in object space (XYZ), comparing it tothe unfolded UV meshes' surface area, and then scaling the UV mesh by thatvalue.

This option is useful when multiple shells are unfolded and you require themto have a similar scale between them.

Scale factor A ratio value that determines the amount of Rescale. A ScaleFactor greater than 1 results in the UV mesh being scaled larger, whereas aScale factor less than 1 results in the UV mesh being scaled smaller.

For example, if a polygon mesh had a unit size of 1 in the scene view, a Scalefactor setting of 0.02 would result in the corresponding UV mesh having aunit size of 0.02 in the UV Texture Editor.

Keep history When Keep History is turned on, the Unfold featureautomatically recalculates the UV texture coordinate positions for the shellwhenever the polygon model’s mesh is changed. This provides an effect wherethe texture appears to be distorted inwards or outwards along the surface whenthe mesh is deformed.

Turning Keep History on can result in long computation times when thepolygon object is animated thereby affecting interactive performance. It shouldbe turned on only when you specifically want this special effect to occur andare aware of the impact on interactive performance in your scene as a result.

The default setting is off.

Solver weighting example

The following example demonstrates how changing the Weight solver towardsoption in combination with pinning and aligning UVs helps to control theunfolded UV layout and the texture mapping that results.

■ A barrel shaped polygonal object is texture-mapped with a checker texture.Using the Unfold feature and performing an initial unfold with the Weightsolver towards option set to 0 (the default) initially produces a tapered UVlayout in the UV Texture Editor. The resulting texture map is skewed anddistorted on the object.


■ A second unfold operation is performed with the Weight solver towardsoption at 0.6. This unfolds the UVs in a more global manner and reducesthe tapering that previously occurred. The UV layout is more predictable,but there is some overlap of UVs in the lower left corner of the UV meshresulting in overlap on the texture.


■ Repositioning and pinning the corners of the UV mesh and performinganother unfold with the Weight solver towards set to 0 further relaxes theUVs and removes the overlapping region.

■ The top and bottom rows of UVs are aligned and a final unfold operationis performed with the Weight solver towards option set to 0 with theborders pinned.


Edit UVs > Layout

Repositions the UV shells for selected objects so their arrangement is improved.The desired workflow is generally to lay out UV shells so they are notoverlapping.

Related topics


■ World space, object space, and local space

Edit UVs > Layout >

The default settings give the best results in most situations.

Layout ObjectsSelect the manner in which you want to layout the UV shells.

Edit UVs > Layout | 129

Per object (overlapping) When multiple objects are selected in the scene thisoption specifies to lay out the UV shells for each object individually withinthe UV Texture Editor.

Single object or multiple objects (non-overlapping) Specifies the multipleUVs to be positioned in the UV Texture Editor as if it were one single object.

PrescaleScales the area of the UV Shell proportional to either the surface area of theselected objects in object space or world space before laying out the UVs.Prescale is usually combined with Uniform Scale mode to scale UVs frommultiple objects into a single UV region.

Prescale is only available when Layout Objects is set to Single or MultipleObjects (non-overlapping).

None No prescaling occurs.

Object Automatically scales the UV shell to accommodate the selected objects’surface areas in object space.

For example, the UV Shells for a scene consisting of 5 spheres of radius 1 willappear equal in size using the Object setting regardless of their individualscaling. Scaling only affects the objects’ size in world space.

World Automatically scales the UV shell to accommodate the selected objects’surface areas in world space.

For example, the UV shells for a scene consisting of 5 spheres of radius 1, willappear according to their individual scale sizes.


Separate shellsSpecifies how you want to cut and separate overlapping UV shells.

Off Does not separate overlapping UV shells. Only the Scale option has aneffect.

Folds Separates only shells where the surface normals of overlapping shellspoint in opposite directions. This method is faster, especially for larger models.However, you may be left with overlapping UVs.

All intersecting Separates all shells where the UVs overlap. This is the default.

Flip reversed Flips UV shells that have normals pointing in opposite UVwinding order.

TIP If your model is symmetrical (for example, a character’s face), you can savetexture space by turning this option off and superimposing the UV shells so theyoccupy the same texture space.

Shell LayoutSpecifies where the UV shells will lie in UV texture space.

None Does not lay out UV shells after they have been cut. Some shells maylie on top of others.


Along U Positions the UV shells along the U axis.

Into Region Positions the UV shells to lie within the 0 to 1 texture space. Thisis the default setting.

Scale modeSelect how you want the UV shells scaled within the UV texture space.

None Performs no scaling.

Uniform Scales the shells to fit the 0 to 1 texture space without changing theaspect ratio. This is the default.

Stretch to region Stretches the UV shells to fit within the 0 to 1 texture space.The UV shells may become distorted as a result.

Shell stackingDetermines how the UV shells get stacked in relation to each other when laidout in the UV Texture Editor.

Bounding box Creates a rectangular bounding box around each UV shell,then stacks the shells based on the borders of the bounding boxes. The UVshells will have more space between them when this option is set.

Shape Stacks the UV shells based on the boundaries of each individual shell.The UV shells can be more tightly arranged to fit into any available spaceswhen this option is set.

RotateAllows the UV texture shells to be rotated in order to better fit the UV texturespace.

None Specifies that the UV shells will not be rotated.

90 degrees Specifies that some UV shells can be rotated by 90 degrees tomaximize the space within the 0 to 1 UV texture space.


Free Rotates the UV shells so they are oriented vertically in the UV TextureEditor based on their longest axis. This aids the Layout feature in packing theshells more densely, thereby maximizing UV texture space.

Spacing presets Layout UVs creates a bounding box around each UV shelland then lays out the UVs so that the individual bounding boxes are positionedclose together. Sometimes when the borders of two UV shells are positionedvery close to each other, the two UV shells may end up sharing the same pixelson a texture map.

When this situation occurs, a portion of one texture may bleed onto anotheror may wrap incorrectly on the surface, resulting in visual artifacts. Whenpainting a texture, overscanning can also cause the paint to spill onto theadjacent piece.

To avoid this situation, you’ll want to specify a spacing preset to ensure thatthere is at least one pixel separating the individual UV bounding boxes. Selecta preset that corresponds to your texture map size. If you don’t know the size,select a smaller map, which will result in a larger spacing between adjacentshells in the UV space. (The smaller the map in pixels, the bigger the UVspacing must be between bounding boxes.)

Select Custom to set the size of the space as a percentage of the map size (inthe Percentage space box) and enter a distance value that is appropriate foryour texture map.

Percentage space When the Spacing presets is set to Custom you can specifya distance measurement to specify the space between bounding boxes as apercentage of the map size.

Region Preset A set of common settings for Scale U, Scale V, Offset U andOffset V. The following table outlines the presets.

Offset VOffset UScale VScale ULabel

0.00.00.51.0Bottom Half

0.50.00.51.0Top Half

0.00.01.00.5Left Half


Offset VOffset UScale VScale ULabel

0.00.51.00.5Right Half

0.00.00.50.5Bottom Left

0.00.50.50.5Bottom Right

0.50.00.50.5Top Left

0.50.50.50.5Top Right

0.00.01.01.0Full Square

Scale U Lets you set the scale of the UV mapping in the U direction. You canuse the Offset in conjunction with the Scale to define the area on your modelupon which your texture is laid out.

Scale V Lets you set the scale of the UV mapping in the V direction. You canuse the Offset in conjunction with the Scale to define the area on your modelupon which your texture is laid out.

Offset U Lets you set the UV mapping so that each UV is a specific distancein the U direction from its default position at the lower left corner of the UVlayout region. You can use the Offset in conjunction with the Scale to definethe area on your model upon which your texture is laid out.

Offset V Lets you set the UV mapping so that each UV is a specific distancein the V direction from its default position at the lower left corner of the UVlayout region. You can use the Offset in conjunction with the Scale to definethe area on your model upon which your texture is laid out.

Edit UVs > Cut UV Edges

Splits UVs along the selected edges creating new texture borders as a result.This feature is also available from the toolbar of the UV Texture Editor.


Related topics


■ Edit UVs > Merge UVs on page 136

Edit UVs > Split UVs

Separates UVs from each other along the edges connected to the selected UVpoints, creating borders. This feature is also available from the toolbar of theUV Texture Editor.

Edit UVs > Sew UV Edges

Attaches UVs along the selected borders, but does not move them together inthe UV Texture Editor view. This feature is also available from the toolbar ofthe UV Texture Editor.

Related topics


■ Edit UVs > Move and Sew UV Edges on page 135

Edit UVs > Move and Sew UV Edges

Move and Sew UV Edges combines separate UV shells along their selectedborder edges by moving one selected UV shell (the smaller one) to the otherselected UV shell (the larger one) and merging the selected edges together sothat one UV shell results. Move and Sew UV Edges is useful for quickly joiningtogether separate UV shells produced by Automatic Mapping or the Layout

Edit UVs > Split UVs | 135

UVs features. This feature is also available from the toolbar of the UV TextureEditor.

There are two options for moving and sewing UV shells: manually orautomatic. The default Move and Sew UV Edges behavior is to manually selectthe edges you want to join and then execute the feature. When the Limit shellsize option is turned on, smaller shells are moved and sewn automatically tothe larger ones based on the Number of faces setting value.

Related topics


■ Edit UVs > Merge UVs on page 136

Edit UVs > Move and Sew UV Edges >

Limit shell size When this option is off, Move and Sew UVs only moves andsews the selected edges.

When this option is on, Move and Sew UVs automatically moves and sewstogether any selected shells below the size set in Number of Faces.

Number of faces When Limit shell size is on, this setting specifies themaximum number of faces in each shell. Larger numbers result in fewer shells.

After performing a Move and Sew operation, you can select the history node(polyMapSewMove) in the Channel Box and adjust the Number of Faces untilyou achieve the results you want.

Edit UVs > Merge UVs

Use Merge UVs to merge together separate UV shells. Merge UVs has a similareffect to Sew UVs. However, Merge UVs is better suited to merging shells whenthe polygon has non-manifold geometry.

For example, when you have three UV shells that all share an edge becausethe geometry is nonmanifold, Merge UVs can combine two of the UV shellswithout affecting the other. If you used Sew UVs in this example, all shellswould be combined because they all share an edge.


Related topics


■ Edit UVs > Cut UV Edges on page 134

Edit UVs > Merge UVs >

Threshold Set the Threshold value to set the maximum distance within whichselected UVs will be merged. Any UVs in the selection that exceed this distancewill not be merged.

Edit UVs > Delete UVs

Removes the UVs from the selected face(s) on a mesh. If you want to maptextures onto the areas of the surface mesh where the UVs have been deleted,you will need to re-map or re-project the UVs using the UV projection mappingfeatures.

Related topics

■ Delete UVs on page 43

Edit UVs > UV Texture Editor

Displays the UV Texture Editor. For more information see UV Texture Editorreference on page 139.

Related topics




Edit UVs > Delete UVs | 137

138

UVs windows and editorsreference

UV Texture Editor

UV Texture Editor reference

The UV Texture Editor (Window > UV Texture Editor or Edit UVs > UV TextureEditor) lets you view and interactively edit UV texture coordinates for polygonsand subdivision surfaces.

You can select, move, scale, and generally modify the UV topology for a surfacevery much like you work with other modeling tools within Maya. You can alsoview the image associated with the assigned texture map as a backdrop withinthe UV Texture Editor and modify the UV layout to match as required.

Items in the UV Texture Editor can be selected from either the menu bar orfrom the graphical toolbar. For more information on the UV Texture Editoroptions see:



Related topics



6

139



■ Delete UVs on page 43



■ Move tool (in UV texture editor) on page 163

UV Texture Editor menu bar

These are descriptions of the menu items in the UV Texture Editor.

Polygons menu

Polygons > Copy UVs

Copies the selected UVs for a selected face to the clipboard so they can becopied (pasted) to another face. See Mesh > Clipboard Actions > CopyAttributes.

Polygons > Paste UVs

Pastes UVs that were previously copied to the selected face. See Mesh >Clipboard Actions > Paste Attributes.

Polygons > Create Empty UV Set

Creates a new, empty UV set on the current object. You can then create theUVs in the set using one of the mapping/projection methods. See Create UVs> Create Empty UV Set on page 107.

Polygons > Copy UVs to UV Set

Use the items in this submenu to create a UV set based on an existing UVlayout or transfer a UV layout from one set to another. See Create UVs > CopyUVs to UV Set on page 108.

140 | Chapter 6 UVs windows and editors reference

Polygons > Set Current UV Set

Lets you select a specific UV set. See Create UVs > Set Current UV Set on page108.

Polygons > Rename Current UV Set

Lets you rename the currently selected UV set. See Create UVs > RenameCurrent UV Set on page 109.

Polygons > Delete Current UV Set

Deletes the currently selected UV set. See Create UVs > Delete Current UV Seton page 109.

Polygons > Normalize

Scales the UVs of the selected faces to within the 0 to 1 texture space. See EditUVs > Normalize on page 110.

Polygons > Unitize

Places the UVs of the selected faces on the boundary of the 0 to 1 texturespace. See Edit UVs > Unitize on page 111.

Polygons > Flip

Flips the positions of the selected UVs. See Edit UVs > Flip on page 111.

This item is also found on the UV Texture Editor toolbar for quick access. SeeUV Texture Editor toolbar on page 154.

Polygons > Rotate

Rotates the positions of the selected UVs by a specified number of degrees.See Edit UVs > Rotate on page 113.


Polygons > Cycle UVs

Rotates the U and V values of the selected polygon.

UV Texture Editor menu bar | 141


Polygons > Best Plane Texturing Tool

Assigns UVs to the faces you select based on a plane computed from verticesyou specify. See Create UVs > Best Plane Texturing Tool on page 107.

Polygons > Grid

Moves every selected UV to its nearest grid intersection in texture space. SeeEdit UVs > Grid on page 114.


Polygons > Align

Aligns the positions of the selected UVs. See Edit UVs > Align on page 114.


Polygons > Warp Image

Modifies a texture image by comparing two UV sets on a single polygonalmesh and produces a new bitmap image. See Edit UVs > Warp Image on page115.

Polygons > Map UV Border

Moves UV borders to the edges of 0 to +1 texture space. See Edit UVs > MapUV Border on page 117.

Polygons > Straighten UV Border

Untangles the border of a UV texture shell, such as an edge that loops arounditself. See Edit UVs > Straighten UV Border on page 120.

Polygons > Relax

Spreads out all UVs to make them easier to work with. See Edit UVs > Relaxon page 121.



Polygons > Unfold

Lets you unwrap the UV mesh for a polygonal object while the feature attemptsto ensure that the UVs do not overlap. See Edit UVs > Unfold on page 123.

Polygons > Layout

Attempts to rearrange the UV shells into a cleaner layout, based on the settingsin the Layout UVs option box. See Edit UVs > Layout on page 129.


Polygons > Cut UV Edges

Separates UVs along the selected edges, creating borders. See Edit UVs > CutUV Edges on page 134.

Polygons > Split UVs

Separates UVs from each other along the edges connected to the selected UVpoints, creating borders. Shortcut for the texture editor’s Edit UVs > Split UVs.


Polygons > Sew UV Edges

Attaches UVs along the selected borders, but does not move them together inthe texture editor view. See Edit UVs > Sew UV Edges on page 135.


Polygons > Move and Sew UV Edges

Attaches UVs along the selected borders, and moves them together in thetexture editor view. See Edit UVs > Move and Sew UV Edges on page 135.



Polygons > Merge UVs

Merges together separate UV shells. See Edit UVs > Merge UVs on page 136.

Polygons > Delete UVs

Removes the selected UVs from the mesh. You will need to re-map or re-projectthe UVs in order to map textures onto the affected areas. See Edit UVs > DeleteUVs on page 137.

Polygons > UV Snapshot

Saves an image file of the current UV layout. You can then paint on this imagein a painting program or use this image as a background reference layer fortexture work in an image editor such as Adobe® Photoshop®. See Save animage of the UV layout on page 48. An option window appears with thefollowing controls:

File Name You can save the file anywhere inside or outside of your project.Maya automatically assigns the file extension based on the image format youselect.

Size X, Size Y Sets the dimensions of the exported image. Use the samedimensions you want for the file texture you are about to create. If you arenot sure, use the default size; you can scale the exported image later in yourpaint program.

Keep Aspect Ratio The aspect ratio is the ratio of Size X to Size Y. With itturned on, you can change one size slider and Maya automatically adjusts theother size value to keep the same ratio. If you need to change the aspect ratio,turn off this option temporarily and adjust one of the sizes.

Color Value Sets the color of the UV patches in the exported image. Thebackground of the snapshot is black; therefore, the Color Value should bewhite or another contrasting color. You can click the box to open the ColorChooser.

Anti-alias Lines Controls whether lines in the output image have anti-aliasing.

Image Format Use an image format that your paint program can read. If yourequire an alpha channel while painting, use TIFF or a similar format.

UV Range Normal (0 to 1) specifies the range between 0 and 1. When thisoption is set (default), only the UVs appearing in the 0 to 1 area are includedin the 2D image that gets output. (This was the option previous to Mayaversion 7.)


Entire Range specifies that a 2D image will be output that covers all displayedUVs regardless of their position within UV space. That is, if the UVs lie outsidethe 0 to 1 range, they will still be included in the UV snapshot image.

User Specified allows you to customize the UV range that will be output byspecifying minimum and maximum values for U and V. This is useful whenyou need to output an image of a specific UV shell or a specific region withinthe UV Texture Editor.

Subdivs menu

The items in this menu are used for editing UVs on subdivision surfaces.

Subdivs > Cut UV Edges

Separates UVs along the selected edges, creating borders. See Edit UVs > CutUV Edges on page 134.

Subdivs > Layout

Tries to move the UVs into a cleaner layout. See Edit UVs > Layout on page129.

Subdivs > Move and Sew UV Edges

Attaches UVs along the selected borders, and moves them together in thetexture editor view. See Edit UVs > Move and Sew UV Edges on page 135.

Subdivs > UV Snapshot

Saves an image file of the current UV layout. For more information seePolygons > UV Snapshot on page 144.

View menu

View > View Contained Faces

A UV selection filter that displays only the UV faces associated with thecurrently selected UVs in the UV Texture Editor.

View > View Connected Faces

A UV selection filter that displays the UV faces associated with the currentlyselected UVs as well as the UV faces immediately connected to those UV faces.


View > View Faces of Selected Images

A UV selection filter that displays the UV faces associated with the currentlyselected texture image in the UV Texture Editor (Textures > filename).

View > Isolate Select submenu

Lets you show only a subset of all UVs, with the ability to add to and subtractfrom the isolated subset. See Display a subset of UVs on page 33

View > Grid

Shows or hides the texture coordinate grid. Choose View > Grid > to setthe grid options. See Use the UV Texture Editor grid on page 47

Length and Width Controls the overall size of the grid, measured in UVcoordinates. The Length and Width is set to 1 (one) by default, because youtypically want UVs to fit within the 0 to 1 range and this setting clearly showsthe 0 to 1 range.

Grid Lines Every Sets the spacing between grid lines. Grid lines appear inincrements based on the decimal value you specify. This setting affects whereUVs snap if you use the Snap to Grid feature.

Subdivisions Sets the number of lines between each grid line. By default,subdivision lines do not show; you must turn on Subdivision Lines for themto appear.

Display Axes, Grid Lines, Subdivision Lines, Grid Numbers Displays orhides items within the grid.

View > Toolbar

Shows or hides the texture editor toolbar. See the toolbar section below.

View > Frame All

Pans and zooms the texture editor view to show the entire UV set.

View > Frame Selection

Pans and zooms the texture editor to show the selected UVs.


Select menu

The items in this menu are also available on a marking menu when you areworking in the UV Texture Editor. Press ctrl + the right mouse button to accessthem.

Select > Select Contained Faces

Selects the faces contained by the current selection of UVs, edges, or vertices.

Select > Select Connected Faces

Selects all faces that share the currently selected UVs, edges, or vertices.

Select > Select Shell

Selects the entire UV shell containing the current selection.

Select > Select Shell Border

Selects the UVs along the border of the UV shell containing the currentselection.

Select > Select Shortest Edge Path Tool

Selects the shortest path of edges between two or more selection points (verticesor UVs). The Select Shortest Edge Path Tool determines the most direct pathbetween any two selection points and selects the edges in between.

The Select Shortest Edge Path Tool is particularly well suited to selecting along and possibly winding path of edges on a mesh when you need tosubsequently perform a Cut UV Edges operation.

Select > Convert Selection to Faces, Edges, Vertices, UVs

Selects the component type connected to the current selection. For example,if you have faces selected and choose Convert to UVs, Maya will select all UVsconnected to the selected faces.

Tool menu

The items in this menu are also available from the toolbar.


Tool > UV Lattice Tool

Manipulates the layout of UVs as a group by letting you create a lattice aroundthe UVs for deformation purposes.

Lattice Settings

Columns Specifies the number of columns for the current lattice manipulator.The minimum number of columns is 3 and maximum number is 8.

Rows Specifies the number of rows for the current lattice manipulator. Theminimum number of rows is 3 and the maximum number is 8.

Falloff Specifies the lattice manipulator's level of influence or falloff value.

Use Bounding Rectangle When on, the current lattice manipulator cannotextend past the outer edge or boundary of the target geometry.

Snap Settings

The lattice snap settings are relative to each UV affected by the lattice. PixelSnap (Image > Pixel Snap) needs to be on in the UV Texture Editor for the UVLattice Tool Snap Settings to have any effect.

PlacementSelect where control points snap to.

Snap Corner When on, the UV lattice deformer’s control points snap to thecorners of each UV.

Snap Center When on, the UV lattice deformer’s control points snap to thecenters of each UV.


Tool > UV Smudge Tool

Moves the position of selected UVs and their neighboring UVs to a diminishingextent that is user defined.

Smudge Settings

Effect TypeSelect the way the UVs follow the brush tool.

Fixed Moves the selected UVs in the direction of the UV Smudge Tool brush’smovements. UVs appear to follow or move with the brush. This setting movesUVs similar to the way the Soft Modification Tool moves vertices.

Smudge Drags or smudges UVs in the direction of the UV Smudge Tool brush’smovements.

Falloff TypeSelect the way that the UV movement falls off as the brush moves.

Exponential Moves UVs based on the distance they are from the UV SmudgeTool brush. A UV moves exponentially more the closer it is to the brush.

Linear Moves UVs based on the distance they are from the UV Smudge Toolbrush. A UV moves linearly more the closer it is to the brush.

Constant Moves all UVs the same amount in the direction of the UV SmudgeTool brush’s movements.

Smudge Size Sets the size of the UV Smudge Tool brush.

In the UV Texture Editor’s view, you can also press b + drag to resize theSmudge Tool brush.


Pressure Sets the magnitude of the smudge and specifies how much the UVSmudge Tool brush affects the selected UVs.

This is only available when the selected Effect Type is Smudge.

Middle Mouse Initiates When on, middle-drag to smudge the layout of yourUVs. When off, drag to smudge the layout of your UVs.

Tool > Move UV Shell Tool

Lets you select and reposition a UV shell in the 2D view of the UV TextureEditor by selecting a single UV on the shell. You can automatically preventthe repositioned UV shell from overlapping other UV shells. See also UVTexture Editor toolbar on page 154.

Prevent Overlap The Prevent Overlap setting restricts a UV shell from beingaccidentally moved to a position where it would overlap existing UV shellsin the UV Texture Editor view. It is on by default. For example, if you selectand move a UV shell and reposition it to an area that is already occupied byan existing UV shell, the selected shell will do one of the following:

■ Snap back to its previous location (when the overlap is large).

■ Snap to the closest location possible based on the direction you draggedthe UV shell (when the overlap is small).Shell SpacingSpecifies the distance the repositioned UV shell will be separated fromother existing UV shells as a percentage of the map size when Preventoverlap is turned on.

Placement iterationsSpecifies the number of times the tool checks between the start and endpositions when translating one or more UV shells in order to optimallyachieve the Shell Spacing distance without snapping back to the originallocation. A higher number produces the closest result possible, but takeslonger to complete the move. The number of selected UV shells also affectsthe time to complete the move. The default setting is 16.

Tool > Smooth UV Tool

Let’s you interactively unfold or relax UVs. To use this tool, you must firstselect a set of UVs. Then, you can adjust the unfold or relax of the UVs by therespective control to the right. For more information, see Relax and untangleUVs on page 63 or Unfold a UV mesh on page 65.


Pin Borders When on, the border UVs of the selected UV set will not movewhen the Unfold or Relax controls are moved.

Space Allows you to adjust whether you Unfold or Relax the UVs in UV spaceor World space.

Image menu

For more information on using the features in this menu see Display a texturebehind the UVs on page 42.

Image > Display Image

Shows or hides the texture image. This item can also be found in the UVTexture Editor toolbar for quick access. See UV Texture Editor toolbar on page154.

Image > Dim Image

Reduces the brightness of the currently displayed background image. Dimmingthe background image lets you more easily view and select components inthe UV Texture Editor’s view. Selecting the item toggles it on or off dependingon its current state.

Image > Display Unfiltered

Turns off pixel blurring to show exact pixel boundaries. This item can also befound in the UV Texture Editor toolbar for quick access. See UV Texture Editortoolbar on page 154.

Image > Shade UVs

Shades active UV shells in a semitransparent way.

Using Shade UVs you can:

■ Display areas where UVs and UV shells overlap within the 2D view of theUV Texture Editor. Regions where UVs and UV shells overlap are shadedwith more opacity when compared to the default shading. See also Displayoverlapping UVs on page 54.

■ Displays the UV winding order for UV shells as they appear within the 2Dview of the UV Texture Editor. UV shells that are front facing (that is havea clockwise winding order), are shaded blue. UV shells that are back facing


(that is have a counterclockwise winding order), are shaded red. See alsoDisplay UV winding order on page 55.Front facing colorSpecifies the shaded color for UV shells with a clockwise winding order.The default color is blue.

Front facing alphaSpecifies the transparency value for the front-facing shaded UV shells. Avalue of 0 is fully transparent while a value of 1 is fully opaque. The defaultis 0.25.

Back facing colorSpecifies the shaded color for UV shells with a counterclockwise windingorder. The default color is red.

Back facing alphaSpecifies the transparency value for the back-facing shaded UV shells. Avalue of 0 is fully transparent while a value of 1 is fully opaque. The defaultis 0.25.

Image > Display RGB Channels, Display Alpha Channel

Switch between displaying the texture image and its alpha (transparency)channel. These items can also be found in the UV Texture Editor toolbar forquick access. See UV Texture Editor toolbar on page 154.

Image > Pixel Snap

Determines whether or not to automatically snap UVs to pixels. Snapping isto pixel corners or centers. This item can also be found in the UV TextureEditor toolbar for quick access. See UV Texture Editor toolbar on page 154.

PlacementSelect where Pixels snap to.

Snap Corner When on, the selected UVs snap to the corners of other UVs.

Snap to Center When on, the selected UVs snap to the centers of other UVs.

Image > Image Range

Use these settings to change how much of the texture appears in the textureeditor.

Minimum U/V and Maximum U/V You can explicitly set the size of theimage by setting these options, or you can select one of the presets.


PresetsSelect one of the preset image ranges and click Apply.

None The texture space is defined by the Minimum and Maximum U and Vvalues.

Grid Size The texture fills the extent of the grid (defined in the Grid Optionswindow).

Unit Size The texture fills the 0 to 1 (or unit) texture space.

Image > Use Image Ratio

Switches between showing square texture space and texture space with thesame ratio of width to height as the image. This item can also be found in theUV Texture Editor toolbar for quick access. See UV Texture Editor toolbar onpage 154.

Image > UV Texture Editor Baking

Bakes the texture and stores it in memory. See also UV Texture Editor toolbaron page 154.

Baked Texture Resolution The resolution used when baking the texture.

Image > Create PSD Network

Creates an Adobe® Photoshop® texture you can use as a texture map. Whenthis feature is used, a PSD layer of the UVs can be explicitly created to aidpainting of the texture. For more information, see Use PSD Networks as texturesin Maya and Create a PSD file with layer sets from within Maya in the Shadingguide.

Image > Update PSD Networks

When you modify a PSD file in Adobe® Photoshop® that is connected to aMaya PSD node, you can update (refresh) the image in Maya to show themodifications immediately. All PSD networks in the scene are updated. SeeUpdate PSD Networks in the Shading guide.

Textures menu

Select which image texture to show in the UV Texture Editor. Select an imagefrom the drop-down list that appears. If no texture images are assigned thelist appears empty.


UV Sets menu

Select the UV set you want to edit in the UV Texture Editor by selecting thename of the UV set from the drop-down list that appears. See UV sets on page11.

UV Texture Editor toolbar

These are descriptions of the items in the UV Texture Editor toolbar. The UVTexture Editor toolbar lets you readily access many of the frequently useditems that exist within the UV Texture Editor menus. For the features thathave options, you can right-click a button to display its options.

UV Tool buttons

Manipulates the layout of UVs as a group by let-ting you create a lattice around the UVs for de-

UV Lattice Tool

formation purposes. Shortcut for Tool > UV Lat-tice Tool in the UV Texture Editor menu.

Lets you select and reposition a UV shell by select-ing a single UV on the shell. You can automatic-

Move UV Shell Tool

ally prevent the repositioned UV shell from over-lapping other UV shells in the 2D view. Shortcutfor Tool > Move UV Shell Tool in the UV TextureEditor menu.

Moves the position of selected UVs and theirneighboring UVs to a diminishing extent that is

UV Smudge Tool

user defined. Shortcut for Tool > UV SmudgeTool in the UV Texture Editor menu.


Lets you select a path of edges between twovertices on a surface mesh. The Select Shortest

Select Shortest Edge PathTool

Edge Path Tool determines the most direct pathbetween any two selection points and selects thepolygon edges in between.

Let’s you control the amount of unfold or relaxapplied to a selection of UVs by dragging themouse across the screen.

Interactive Unfold/RelaxTool

UV orientation buttons

These items let you edit the orientation and rotation of UVs.

Flips the positions of the selected UVs in the Udirection. Shortcut for Edit UVs > Flip.

Flip U

Flips the positions of the selected UVs in the Vdirection. Shortcut for Edit UVs > Flip.

Flip V

Rotates the positions of the selected UVs by 45degrees in a counterclockwise direction. Shortcutfor Edit UVs > Rotate.

Rotate UVs counterclock-wise

Rotates the positions of the selected UVs by 45degrees in a clockwise direction. Shortcut for EditUVs > Rotate.

Rotate UVs clockwise

Cut and sew UV buttons

These items let you cut and sew UV shells.

Separates UVs along the selected edges, creatingborders. Shortcut for Edit UVs > Cut UV Edges.

Cut UVs along selection

Separates UVs from each other along the edgesconnected to the selected UV points, creatingborders. Shortcut for Edit UVs > Split UVs.

Split UVs

UV Texture Editor toolbar | 155

Attaches UVs along the selected borders, butdoes not move them together in the texture

Sew UVs

editor view. Shortcut for Edit UVs > Sew UVEdges.

Attaches UVs along the selected borders, andmoves them together in the texture editor view.Shortcut for Edit UVs > Move and Sew UV Edges.

Move and Sew UVs

UV layout buttons

Attempts to arrange the UVs into a cleaner lay-out, based on the settings in the Layout UVsoption box. Shortcut for Edit UVs > Layout.

Layout

Moves every selected UV to its nearest grid in-tersection in texture space. Shortcut for Edit UVs> Grid.

Grid UVs

To change the grid, right-click the View Gridbutton on the toolbar.

Unwraps the selected UV mesh while attemptingto ensure that the UVs do not overlap. Shortcutfor Edit UVs > Unfold.

Unfold

Spreads out the selected UV mesh to make iteasier to work with. Shortcut for Edit UVs > Re-lax.

Relax

UV alignment buttons

Aligns the positions of the selected UVs to theminimum U value. Shortcut for Edit UVs > Align.

Align Min U

Aligns the positions of the selected UVs to themaximum U value. Shortcut for Edit UVs > Align.

Align Max U


Aligns the positions of the selected UVs to theminimum V value. Shortcut for Edit UVs > Align.

Align Min V

Aligns the positions of the selected UVs to themaximum V value. Shortcut for Edit UVs > Align.

Align Max V

Isolate selection buttons

These items let you work on a subset of UV faces while hiding the rest.

Switches between showing all UVs and only theisolated UVs. Shortcut for View > Isolate Select> View Set.

Toggle Isolate Select Mode

Adds the selected UVs to the isolated subset.When you click the Toggle isolation button the

Add selected to isolation

selected UVs will be visible. Shortcut for View >Isolate Select > Add Selected.

Removes the selected UVs from the isolatedsubset. Shortcut for View > Isolate Select > Re-move Selected.

Remove selected from isola-tion

Clears the isolated subset. You can then selecta new set of UVs and click Toggle isolation to

Remove all

isolate them. Shortcut for View > Isolate Select> Remove All.

Image and texture buttons

These items let you control the display of images and textures in the UVTexture Editor.

Shows or hides the texture image. Shortcut forImage > Display Image.

Display Image


Switches the background image betweenhardware texture filtering and sharply definedpixels. Shortcut for Image > Display Unfiltered.

Toggle Filtered Image

Reduces the brightness of the currently dis-played background image. Shortcut for Image> Dim Image.

Dim Image

Shows or hides the grid. Shortcut for View > Grid.View Grid

Chooses whether to automatically snap UVs topixel boundaries. Shortcut for Image > Pixel Snap.

Pixel Snap

Shades selected UV shells in a semi-transparentfashion so you can determine areas of overlap orUV winding order.

Shade UVs

Toggles the display of texture borders on UVshells. Texture borders appear with a thick line.

Toggle Texture Borders

Displays the RGB (color) channels of the selectedtexture image. Shortcut for Image > Display RGBChannels.

Display RGB Channels

Displays the Alpha (transparency) channel of theselected texture image. Shortcut for Image >Display Alpha Channels.

Display Alpha Channel

UV texturing buttons

Bakes the texture and stores it in memory. SeeImage > Dim Image on page 151. Shortcut forImage > UV Texture Editor Baking.

UV Texture Editor Baking


Refreshes the PSD textures currently in use forthe scene. When you modify a PSD file (in Pho-

Update PSD Networks

toshop) that is connected to a Maya PSD node(in Maya), you can update (refresh) the imagein Maya to show the modifications immediately.See Image > Update PSD Networks.

Rebakes the texture. If you turn on Image > UVTexture Editor Baking, you must rebake the tex-

Force editor texture rebake

ture (using Force Editor Texture Rebake) aftermaking changes to the texture (File node andplace2dTexture node attributes) in order to seethe effect of those changes.

Switches between showing square texture spaceand texture space with the same ratio of width

Use Image Ratio

to height as the image. Shortcut for Image > UseImage Ratio.

UV edit buttons

Shows the coordinates of the se-lected UVs. Edit the text boxes

U coordinate, V coordinate

and press Enter to move thepoints.

The UV coordinates in the textboxes on the toolbar do not up-

Refresh UV values

date automatically as you movethe selected UV point. Click therefresh button to update the val-ues in the text boxes.

Changes the UV coordinate entrymode between absolute and rel-

UV Transformation Entry

ative values. Also provides entryof UV rotation values.


Copies the selected UV points orfaces (depending on the

Copy

Copy/paste faces or UVs button)to the clipboard.

Pastes UV points or faces (depend-ing on the Copy/paste faces orUVs button) from the clipboard.

Paste

Pastes only the U values on theclipboard onto the selected UVpoints.

Paste U to selected UVs

Pastes only the V values on theclipboard onto the selected UVpoints.

Paste V to selected UVs

Switches the Copy and Pastebuttons on the toolbar betweenworking on UVs and UV faces.

Copy/paste faces or UVs

Rotates the U and V values of theselected polygon.

Cycle UVs

UV Set EditorCreate UVs > UV Set Editor

The UV Set Editor lets you create and edit UV sets for multiple polygon meshessimultaneously.

The UV Set Editor lists only the UV sets for the currently selected polygonmeshes. You must first select the polygon meshes in order to edit the UV sets.

New Creates a new, empty UV set on the currently selected objects. You canthen create the UVs in the set using one of the mapping/projection methods.This feature is the same as Create UVs > Create Empty UV Set.

Rename Lets you rename the currently selected UV set.


Delete Deletes the currently selected UV set. This feature is the same as CreateUVs > Delete Current UV Set.

Copy Creates a new UV set based on an existing UV layout or transfers a UVlayout from one set to another. This feature is the same as Copy UVs to UVSet.

Propagate Assigns the selected UV set from the UV Set Editor list to the selectedobjects in the scene. The selected UV set becomes the active UV set for thoseobjects.

Unmapped Selects unmapped faces on any selected objects in the scene. Thisaids in visually determining any areas where texture maps do not appear orappear incorrectly.

UV Set Editor | 161

162

UVs tool reference

Move tool (in UV texture editor)The Move tool has different options when you work in the UV texture editorpanel.

Retain Component Spacing When this option is off, if you snap to a point(with grid snapping, point snapping, or pixel snapping), all selected UVs snapto the same point, bunching them up.

When this option is on, if you snap to a point, the selected UVs keep theirpositions relative to each other.

7

163

164

Index

A

Add selected to isolation (UV toolbutton) 157

Adobe Photoshop texture, using as texturemap 153

align UVs 114tool buttons 156

alpha channeladjust for UV shells 151display 152include (Warp image option) 116

artwork, mapping onto character 4aspect ratio, preserve when normalizing

UVs 111assign shader to projection 28attaching UV shells 52automatic UV mapping 22

options 102projection manipulator 23separating, merging, attaching UV

shells 52user-defined projection 25

B

backdrop image, arranging UVs to 42Background color (Warp image

option) 116background image, dimming 151Background mode (Warp image

option) 115baking

per-instance UV sets 91UV texture 153

Best plane (Planar Mapping option) 97Best Plane Texturing Tool 107Bilinear Filtering (Warp image

option) 116borders (see UV borders) 122boundaries (see UV borders) 63

Bounding box (Planar Mappingoption) 97

C

camera view, use as planarprojection 106

circlemapping UV border to 118mapping UVs to 60

Clipboard ActionsMesh menu 80

Collectively (Normalize UVs option) 110colors

adding for UV shells 151copying between polygons 80UV sets for 13

componentsUVs, selecting 32

confirming UV placement 28Constrain UVs (Unfold option) 125converting UV selection 33Copy (UV tool button) 160Copy UVs to UV Set 84, 108Copy/paste faces or UVs (UV tool

button) 160Create Empty UV Set 83, 107Create PSD Network (UV Texture

Editor) 153Create UVs Based On Camera 106creating

per-instance UV sets 90Cut UV Edges 134Cut UV Edges (Edit UVs menu) 134Cut UVs along selection (UV tool

button) 155Cycle UVs (UV tool button) 160Cylindrical Mapping 99cylindrical UV mapping 19

options 99

165 | Index

D

decal sheet, UV mapping 4Delete Current UV Set 84, 109Delete UVs 43, 137deleting

UVs 137Dim Image (UV tool button) 158Display Alpha Channel (UV tool

button) 158Display Image (UV tool button) 157Display RGB Channels (UV tool

button) 158displaying

UVs 31distortion

of texture maps, minimize withUnfold 65

E

edge path, selecting shortest 147edges (see UV borders) 122Edit NURBS UV mode 93examples

brick wall with spray paint ontop 12

mapping artwork on gamescharacter 4

UVs needing editing 4warp image applications 45weight solver while unfolding

UVs 126

F

facesselecting 147selecting from UV components 33showing those inside selected UVs or

edges 35falloff

UV Smudge tool 149file format

Warp image option 116

FlipUVs 111

flippingreversed UV shells (Layout

option) 131selected UV shells 111UV faces 36UV shells 79UV tool buttons 155

G

gridin UV Texture Editor 47reposition UVs to 114UV tool button 156

GridUVs 114

H

history, keep (Unfold option) 126

I

Image menuUV Texture Editor 151

Image Range (UV Texture Editor) 152image ratio

change in UV Texture Editor 153images

assigned, viewing UVs with 34background, dimming 151creating by comparing UV sets 115keeping width/height ratio (Planar

Mapping option) 98minimizing distortion with

Unfold 65tile (Warp image option) 117using to arrange UVs 42warping 45

Interactive Unfold/Relax Tool (UV TextureEditor)

tool button 155isolating UVs 33

166 | Index

L

lattice tool for UVs 49options 148

layered texture, UV sets 13Layout

UVs 129layout of UVs (see UV layout) 129light baking 11lighting

information in UV sets 11limitations

per-instance UV sets 93

M

manipulatorprojection, for automatic

mapping 23Map UV Border 61, 117mapping UVs 6

to a square or circle 60marking menus

UV Texture Editor 10Merge UVs 136Merge UVs (Edit UVs menu) 136merging

UV shells 52meshes (see surface meshes) 29Move and Sew UV Edges 135Move and Sew UVs (UV tool button) 156Move UV Shell Tool (UV Texture

Editor) 150tool button 154

movingUVs 35

multi-texturing with multiple UVlayouts 11

N

New Image Name (Warp Imageoption) 115

non-manifold geometrymerging polygons 136

Normalize 110

normalize UVs 110NURBS surfaces

assigning textures 2editing UV texture coordinates 93

O

objects, defining for UV projection 26orientation of UVs, buttons 155overlapping

UV shells 6UVs 5UVs, viewing 54

Overwrite existing file (Warp imageoption) 116

P

Paste (UV tool buttons) 160Per Instance Shared 87Per Instance Unshared 87per-instance UV sets 87

baking 91creating 90example 88limitations 93

Percentage Space (Automatic mappingoption) 106

perspective viewdisplaying with UV Texture Editor 9

Photoshop texture, using as texturemap 153

pinning UVs on border 63Relax option 121Unfold option 124

Pixel Snap (UV tool button) 158pixels

blurring, turning off 151snap UVs to 152switching between blended and

sharp-edged 42Planar Mapping 97planar UV mapping 15planes

creating from vertices forprojection 107

Index | 167

defining for projected UVmapping 25

mapping UVs 15polygon meshes

techniques for UV mapping 3transfer UVs between 29unfold 65unfold and relax example 73unfold setup 66

polygonsassigning textures 2copying UVs, colors, shaders

between 80surface meshes, creating UVs 3tasks in UV Texture Editor 10

Polygons menu (UV Texture Editor) 140Delete UVs 44Unfold 65

pre-lighting surfaces 11projecting UVs

assign shader 107automatically from multiple

planes 22criteria for user-defined objects 26cylindrical 19defining planes 25from specified plane 107insert before deformers (Automatic

mapping option) 103insert before deformers (Cylindrical

mapping option) 99insert before deformers (Image

Mapping option) 98planar (one plane) 15spherical 21use camera view 106

projection manipulatorBest plane option 97Bounding box option 97manually adjusting 98

R

rectangleplace around UVs (lattice) 148

Refresh UV values (UV tool button) 159

RelaxUVs 63

Relax (Edit UVs menu) 121description 63untangling UVs first 117UV tool button 156

Rename Current UV Set 84, 109resolution

warp image options 116reversing

UV shell 79UV wounds 79

RGB channels, display 152Rotate

UVs 113UVs diescreetly 37

Rotate UVs (UV tool buttons) 155rotating

UV shells 79UV shells for best fit (Layout

option) 132UVs, description 35UVs, tool buttons 113

S

Scale modeautomatic mapping option 104

scalingUVs 35

scene viewselecting UVs 32

Select menu (UV Texture Editor) 33, 147Select Shortest Edge Path Tool (UV Texture

Editor) 147tool button 155

selectionconverting to faces, edges, vertices,

UVs 147UVs, UV components, UV shells 32

semitransparent display of UVs 54separating UV shells 52Set Current UV Set 108Sew UV Edges 135

UV tool button 156

168 | Index

Shade UVs 54description 54using¶ 55UV tool button 158UV winding order 55

shadersassign to projection 107copying between polygons 80

shadingstoring information in UV sets 11

sharingUV sets 87

Shell stacking (Automatic mappingoption) 105

shells (see UV shells) 6shortest edge path, selecting 147smudge tool (UVs) 51

settings 149snap UVs to grid 47snapping

UVs 38Source image name (Warp Image

option) 115spacing between UV shells 7Spacing presets

Automatic Mapping option 105Layout option 133

Spherical Mapping 100spherical UV mapping 21

options 100Split UVs 135Split UVs (Edit UVs menu) 135

tool button 155square

mapping UV border to 117mapping UVs to 60

stacking UV shells (Layout option) 132Straighten UV Border 63, 120straightening border UVs 62

options 120subdivision surfaces

assigning textures 2editing 145exporting image of UVs 48tasks in UV Texture Editor 10

Subdivs menu (UV Texture Editor) 145UV Snapshot 48

subset of UVs, displaying 33surface meshes

creating UVs for 2NURBs 2polygons 2subdivision surfaces 2techniques for UV mapping 3

surfacespre-lighting 11

T

texture coordinates (see UVs) 1texture image

modify using UV sets 115texture maps 1

distorted 5for surface types 2minimize distortion with Unfold 65placement on 3D surfaces 1use Adobe Photoshop texture 153

texture space, UV 1textures

assigning to a UV set 85flipping 36repeating with UV range 6thicken borders 41

Textures menu (UV Texture Editor) 153Tiled (Warp image option) 117Toggle Filtered Image (UV tool

button) 158Toggle Isolate Select Mode (UV tool

button) 157Toggle Texture Borders button (UV Texture

Editor button) 41tool buttons, UV Texture Editor 154Tool menu

UV Texture Editor 147transparency

UV sets for 13

U

U coordinate (UV tool button) 159

Index | 169

UnfoldUVs 123

Unfold UVs 65unfolding 65

description 65polygon UV texture mesh 70preparing 68tips 70tool button 156UV mesh 123

UnitizeUVs 111

unitizing UVs 111untangling UVs

at borders 117before mapping 60interior 63

unwrappingUV meshes with minimal

distortion 65Update PSD Networks (UV tool

button) 159Use Image Ratio (UV tool button) 159user-defined UV mapping 25

criteria for projection objects 26UV borders

creating by splitting along selectedUVs 135

creating by splitting UV edges 134moving and sewing together 135pinning to untangle interior 63pinning UVs on (Relax option) 121pinning UVs on (Unfold

option) 124positioning 117selecting 147sewing 135straightening 62straightening, options 120unitizing 111untangling 60weighting 122

UV componentsselecting 32

UV Lattice Tool 49description 148

tool button 154UV layout

modify 49options 129UV shells 58UV tool button 156

UV mappingautomatic (for best placement) 22cylindrical 19definition 2planar 15production workflow 4spherical 21user-defined 25

UV meshes 4reassembling 5transfer UVs between 29unfold and relax example 73unfold setup 66unfolding 65unwrapping 123unwrapping with minimal

distortion 65UV sets 11

assigning textures to 85compare to produce image 115comparing to create warp image 45copying UVs to another 86creating 83deleting 84deleting current 109duplicating 84empty, creating 107for a layered texture 13for color and transparency 13menu (UV Texture Editor) 154overview 11per-instance 87polygon mesh, specifying for 108renaming 84renaming current 109sharing 87source and destination, warp image

options 116storing shading and lighting

information 11

170 | Index

switching between 84UV shells 6

automatic mapping 23avoid overlapping 6changing orientation 79components, selecting 32exporting image of 48flipping 111flipping reversed (Layout

option) 131laying out automatically 58layout options 104merge together 136moving 36, 150positioning UVs on border 117rearrange layout 129scaling options (automatic

mapping) 104scaling, stretching, flipping,

arranging 58selecting 147selecting from UV components 33selecting UVs 32separating (Layout option) 131separating, merging and

attaching 52shading 151spacing between 7spacing presets option 105stacking options 105straightening border UVs 62untangling border UVs 60untangling interior UVs 63

UV Smudge Tool 51description 149tool button 154

UV Snapshot 48description 48options 144Subdivs menu 48

UV Texture Editor 8adjust size of image 152Align UV buttons 156baking 153Baking (UV tool button) 158changing UV shell orientation 79

copying UVs from one UV set toanother 86

Create PSD Network 153displaying a subset of UVs 33displaying with perspective view 9dollying and tracking 41editing UV texture coordinates

(NURBS) 93grid 6, 47Image menu 151marking menus 10menu items 140overview 8Polygons menu 140Select menu 33, 147selecting UVs 32separate menus for UV tasks 10Shade UVs 55smudge UV layout 51Subdivs menu 145switching between UV sets 84Textures menu 153thicken texture borders 41tool buttons 154Tool menu 147toolbar options 154using image to arrange UVs 42UV Lattice Tool 49UV Sets menu 154UV snapshot of subdivision

surfaces 48View menu 145viewing items 10viewing overlapping UVs 54viewing UVs 31Warp Image 45

UV tool buttons, UV Texture Editor 154UV Transformation Entry (UV tool

button) 159UVs 1

aligning 114aligning to grid 114aligning, buttons 156arranging 6arranging using an image

backdrop 42

Index | 171

automatic mapping 22best placement 22confirming placement 28constrain (Unfold option) 125converting selection 33copying between polygons 80copying to new UV set 108creating 3definition 1deleting 43discrete rotate and scale 37displaying 2D texture coordinates

with 3D scene view 9displaying a subset 33displaying if texture image

assigned 34distorted projection 5editing for NURBS surfaces 93evaluating 4image of shell layout 48lattice, placing around 148layout of shells 58mapping techniques 3mapping tips 6menu reference 97moving, rotating, scaling 35multiple layouts 11normalizing 110orientation, changing 155overlapped, viewing 54overlapped, why not desirable 5overlapping shells 6overview 1pin (Unfold option) 124positioning on border of UV

shell 117repeating texture 6rotating 113selecting components 32separating, merging and attaching

shells 52sets, creating 83sewing along edges 135smudge layout 51

snapping 38snapping example 38snapping to grid 47snapping to pixels 152splitting along edges 134splitting along selected path 135straightening borders 62tasks in UV Texture Editor 10tips 4transferring between meshes 29unitizing 111untangling at borders 60untangling interior 63viewing in UV Texture Editor 31winding order 55zooming in or out to see 41

V

V coordinate (UV tool button) 159vertices, create projection plane

from 107View Grid (UV tool button) 158View menu (UV Texture Editor) 145viewing UVs 31

W

warp image 45applications 45description 45options 115

Warp ImageUVs 45, 115

weight solverUnfold UVs 123workflow example 126

winding order of UVs 55

Z

zoomingto show all UVs 41

172 | Index

Documents

Maya MappingUVs