Volumetric Illustration: Volumetric Illustration: Designing 3D Models with Designing 3D Models with

Internal TexturesInternal Textures

Shigeru Owada Frank Nielsen Makoto Okabe Takeo Igarashi

The University of TokyoSony CS Laboratories Inc.

SIGGRAPH 2004

AbstractAbstract

Outline Outline

IntroductionIntroduction Related workRelated work User interfaceUser interface AlgorithmAlgorithm ResultsResults Conclusions and future workConclusions and future work

Introduction (1/3)Introduction (1/3) The application of a surface representation The application of a surface representation

is limited because it lacks internal is limited because it lacks internal information.information.

Volumetric representations have Volumetric representations have complementary advantages and complementary advantages and limitations.limitations.• Modeling is especially problematic.Modeling is especially problematic.

The main source of volume data are the The main source of volume data are the capture of real-world objects and capture of real-world objects and procedural design.procedural design.• Not appropriate for drawing quickly for Not appropriate for drawing quickly for

communication purpose.communication purpose.

Introduction (2/3)Introduction (2/3)

Our goal is to develop an interactive Our goal is to develop an interactive designing and browsing system.designing and browsing system.

Cannot see all of the 3D volumetric Cannot see all of the 3D volumetric information simultaneously.information simultaneously.• Can see only one 2D cross-section at a time.Can see only one 2D cross-section at a time.

System synthesizes the internal textures for a cross-section by using 2D reference images instead of maintaining all the 3D volumetric data• Providing guiding information.Providing guiding information.

Introduction (3/3)Introduction (3/3)

Technical contributions:Technical contributions:• Interface used to assign internal textures to a given Interface used to assign internal textures to a given

surface mesh.surface mesh.• Algorithms that synthesize texture on a cross-sectiAlgorithms that synthesize texture on a cross-secti

on.on. Allowing non-experts to create volumetirc illusAllowing non-experts to create volumetirc illus

trations rapidly.trations rapidly.

Outline Outline

IntroductionIntroduction Related workRelated work User interfaceUser interface AlgorithmAlgorithm ResultsResults Conclusions and future workConclusions and future work

Related work(1/2)Related work(1/2)

Volumetric modeling:Volumetric modeling:• [Perlin 1985; Kniss et al. 2002] Using procedural methods whiUsing procedural methods whi

ch enable the user to design various 3D structure.ch enable the user to design various 3D structure.• [Banvard 2002] Using special-purpose instruments to get the Using special-purpose instruments to get the

volumetric data.volumetric data. Texture synthesis:Texture synthesis:

• [Heeger and Bergen 1995] frequency domain.frequency domain.• [Efros and Leung 1999; Wei and Levoy 2000] pixel-based.pixel-based.• [Efros and Freeman 2001; Kwatra et al. 2003] patch-based.patch-based.• [Stam 1997;Cohen et al. 2003] non-periodic tiling.non-periodic tiling.

Related work(2/2)Related work(2/2)

Non-photorealistic modeling and rendering:Non-photorealistic modeling and rendering:• [Lake et al. 2000; Kalnins et al. 2002] the stylized rendering of the stylized rendering of

3D models that synthesize interesting 2D pictures by adding d3D models that synthesize interesting 2D pictures by adding details to simple 3D geometries on the flyetails to simple 3D geometries on the fly

Our system provides a tailored user interface fOur system provides a tailored user interface for intuitively designing volumetric illustrationor intuitively designing volumetric illustrations.s.

Outline Outline

IntroductionIntroduction Related workRelated work User interfaceUser interface AlgorithmAlgorithm ResultsResults Conclusions and future workConclusions and future work

User interfaceUser interface

The system comprised two functions: The system comprised two functions: browsing and modeling.browsing and modeling.

Browsing interface:Browsing interface:• The browsing interface is a subset of the The browsing interface is a subset of the

modeling interface.modeling interface.• A standard 3D model viewerA standard 3D model viewer

Inspection of internal texture using a cut operation.Inspection of internal texture using a cut operation. Rotating and translating the model.Rotating and translating the model. The user can cut the model by drawing a freedom The user can cut the model by drawing a freedom

stroke that crosses the model on the screen.stroke that crosses the model on the screen.

Modeling interfaceModeling interface The modeling process has the following The modeling process has the following

steps:steps:1.1. Cut the target 3D model and specify a 3D Cut the target 3D model and specify a 3D

region to be textured by clicking on the cross-region to be textured by clicking on the cross-section.section.

2.2. Choose one of the three texture types to use Choose one of the three texture types to use for the region.for the region.

3.3. Import a reference 2D image.Import a reference 2D image.4.4. Establish the correspondence between the Establish the correspondence between the

2D reference image and the cross-section of 2D reference image and the cross-section of the 3D model by providing the necessary the 3D model by providing the necessary guidance information.guidance information.

5.5. Repeat steps 1-4 for each 3D region.Repeat steps 1-4 for each 3D region.

Modeling interfaceModeling interface

Modeling interfaceModeling interface

The current system supports three types The current system supports three types of texture: isotropic, layered, and orientedof texture: isotropic, layered, and oriented

Isotropic texturesIsotropic textures

Layered texturesLayered textures

Layered texturesLayered textures

Oriented texturesOriented textures

Outline Outline

IntroductionIntroduction Related workRelated work User interfaceUser interface AlgorithmAlgorithm ResultsResults Conclusions and future workConclusions and future work

Algorithms Algorithms

Using the curved plane made by cut operation ,Using the curved plane made by cut operation , a model is divided by CSG operation [Hoffman a model is divided by CSG operation [Hoffman 1989].1989].

Isotropic textures:Isotropic textures:• No dependency on position or direction.No dependency on position or direction.• Simply using a standard 2D texture-synthesis algorSimply using a standard 2D texture-synthesis algor

ithm. [Wei and Levoy 2000; Cohen ithm. [Wei and Levoy 2000; Cohen et alet al. 2003; Kwatr. 2003; Kwatra a et alet al. 2003]. 2003]

AlgorithmAlgorithm

Layered textures:Layered textures:• The system generates a reference control map The system generates a reference control map

for the reference image and a target control for the reference image and a target control map for the cross-section.map for the cross-section.

• A control map is grayscale 2D imageA control map is grayscale 2D image The grayscale value represent a smooth 2D depth The grayscale value represent a smooth 2D depth

field.field. Upper bound 0, lower bound 1.Upper bound 0, lower bound 1.

• Using a Using a thin-plate interpolation technique thin-plate interpolation technique to to compute the smooth depth field.compute the smooth depth field.

AlgorithmAlgorithm

• Using a pixel-based technique which similar to Using a pixel-based technique which similar to field distortion synthesis to start texture field distortion synthesis to start texture synthesis process.synthesis process.

But have some difference.But have some difference.

AlgorithmAlgorithm

Oriented textures:Oriented textures:• The synthesis process for an oriented texture The synthesis process for an oriented texture

requires a 3D reference volume and a flow field requires a 3D reference volume and a flow field defined in the 3D region in the surface mesh.defined in the 3D region in the surface mesh.

• The system computes the color for each pixel The system computes the color for each pixel in the cross-section.in the cross-section.

Outline Outline

IntroductionIntroduction Related workRelated work User interfaceUser interface AlgorithmAlgorithm ResultsResults Conclusions and future workConclusions and future work

Results Results

ResultsResults

ResultsResults

ResultsResults

Outline Outline

IntroductionIntroduction Related workRelated work User interfaceUser interface AlgorithmAlgorithm ResultsResults Conclusions and future workConclusions and future work

Conclusion and future workConclusion and future work

A modeling and browsing system that A modeling and browsing system that adds internal textures to a surface mesh.adds internal textures to a surface mesh.

This system will be useful for conveying This system will be useful for conveying volumetric information.volumetric information.

In future work , improve the performance In future work , improve the performance and quality of the overall process.and quality of the overall process.