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3D GARMENT DESIGN AND ANIMATION
–– A New Design Tool For The Garment Industry
Ying Yang, Nadia Magnenat ThalmannMIRALab, CUI
Université de Genève12 rue du Lac
CH 1207 GenèveSwitzerland
Daniel ThalmannComputer Graphics Lab
Swiss Federal Institute of TechnologyLausanne
Switzerland
ABSTRACT
Garment design is traditionally carried out in two dimensions, and some software has been
developed and applied in the garment industry in the design of garment panels. In this paper,
a new tool for the interactive design of garments in three dimensions is introduced. Making
use of an elastic surface model, animation allows us to examine the garment design in three
dimensions dynamically. The designer can use this tool to visualize his original ideas and
changes interactively, and to see the garment vividly portrayed including texture mapping on
the final design, before the real cloth panels are cut. Application of this tool in the garment
industry could potentially reduce design time and costs substantially.
Keywords: cloth animation, garment panels, deformable models
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1. INTRODUCTION
As in many other industries, computers are being considered for use in the garment industry
for both design and manufacturing. The traditional approach to garment making is first to take
measurements of the human body, second to draw panel patterns on rectangular fabrics in two
dimensions according to the style and fashion desired, then to cut the panels out, and finally
to sew them together by hand or by sewing machines. Before the dress is sewn the tailor
cannot know for sure what the dress will look like, and what the effect will be of wearing it
on the human body. For a new fashion design, the tailor can only imagine the results,
depending on his experience and talent.
In recent years, computer technologies have begun to be used in the garment industry.
Software has been developed and applied to the interactive design of 2D garment panels and
to optimizing the layout of garment panels on the fabric. In Hinds and McCartney's work
[2], a static trunk of a mannequin's body is represented by bicubic B-spline surfaces. Garment
panels are considered to be surfaces of complex shapes in 3D. The garment panels are
designed around the static mannequin body, and then are reduced to 2D cutting patterns. This
approach is contrary to the traditional approach to garment design. The garment is modelled
by geometric methods. To visualize the folds and drapes, harmonic functions and sinusoidal
functions are superimposed on the garment panels. In Mangen and Lasudry's work [8], an
algorithm is proposed for finding the intersection polygon of any two polygons. This is
applied to the automatic optimization of the layout of polygonal garment panels in 2D
rectangular fabrics. Both of these projects concern stages of garment design and manufacturing
in real industrial contexts.
Computer techniques of graphics offer many other possibilities for the development of
high-tech tools for garment design and manufacturing. Not only can the interactive design of
2D garment panels be achieved by general computer graphics, but the sewing of garment
panels and the examination of garment movement on the human body can also be visualized
through cloth animation based on dynamic surface models. Terzopoulos et al. [9] and Aono
[1] both proposed elastically deformable surface models to simulate and animate the
movement of cloth in various physical environments. Another interesting approach by Kunii
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and Gotoda [4] incorporates both the kinetic and geometric properties for generating garment
wrinkles. Magnenat Thalmann et al. used a modified elastic model to create and animate
various articles of clothing, such as a skirt, underwear, T-shirt and trousers, on a synthesized
actor's body [6][7]. Based on the above techniques, we are developing a new design tool for
use in the garment industry. This tool interactively designs the garment panels in 2D by
computer, sews the garment panels in 3D on the computer screen, and dynamically simulates
the garment's shape on the moving body of a synthesized actor. Texture patterns of various
fabrics can be mapped onto the garment to make it look more realistic. The designer can
modify the 2D panels if the 3D garment is not satisfactory. After all the examinations and
changes, the final design is drawn by a plotter or is directly sent to a cutting machine which
cuts the garment panels out of the fabric. A pattern library of garment templates can be
connected to this tool. Adding A.I. techniques, it would be possible for the tool to
automatically design garments for the public.
In the following sections, the strategy and tactics of the tool are sketched out.
2. A SYSTEM FOR INTERACTIVE GARMENT DESIGN
The system for the interactive garment design tool consists of following five parts:
1) Interactive Graphic Interface for the 2D Design of Panels.
2) Deformable Cloth Model.
3) Pattern Library of Garment Templates.
4) Movable Human Body Model.
5) Output Interface.
The structure and the relationships of the system are as Fig.1
The interactive graphic design of the garment panels is carried out within the 2D design
interface. With cursor movements of the mouse, the designer can draw and modify the
patterns for the garment panels on the coordinate grid on the computer screen in two
dimensions. The garment templates in the library can be loaded into the 2D design interface,
so that they can be used or modified. The 3D human body model provides the movable
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mannequin bodies and the motion sequences. Different sequences of human movements, such
as walking, running, dancing, fashion modelling, and so on can be generated. The 3D
deformable cloth model is used to create the garment from the fabric panels in three
dimensions, and to simulate the changing shape of the garment on the mannequin as the body
moves. Various properties of the cloth fabric, such as its mass, stretching and bending factor
coefficients, damping density as well as characteristics of the physical environment, such as
gravity and wind forces, are used to simulate the movements of the garment. In the template
library, there are patterns of many different ruled or traditional garments. These templates can
be used directly in the design or modified for the particular individuals. After the design is
finally decided upon, the patterns for the panels in the final design are saved in the library.
The patterns can be drawn on papers by a plotter or sent to the cutting machine to produce
garment templates and the cloth panels.
3. 2D PANEL DESIGN
The functions of the 2D panel design interface include mainly interactive drawing of the panel
polygons, digitizing existing templates, and optimal placement of garment panels on
rectangular fabrics of various sizes. Button positions, seam lines, and the sizes of the panels
and garment, are also indicated on the patterns.
3.1. DIGITIZATION OF TEMPLATES
Many templates already exist for various fashion styles of different peoples, for different
body shapes, in different countries. They are the most valuable resources for the garment
designer. Putting them in the template library is helpful in that the designer can easily access
them and modify them slightly to make new garments. This requires digitalization of the
existing templates. Only the tablet and mouse need be used to digitize the templates is
polygonal sometimes with some curvilinear arc edges. The arc edges can be simplified to
several terminal lines, so that all templates can be regarded as simply polygonals. With the
tablet and mouse, starting at one vertex of the polygon, the shape of the garment can be
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digitized into the library vertex by vertex. For curvilinear edges, additional points are chosen
to be vertices.
3.2. INTERACTIVE PANEL DESIGN
Less complicated than other CAD systems in mechanics or architecture, the interactive
garment panel design is carried out in only two dimensions. Because all the panels can be
simplified to polygons, the designer can easily create and modify their shape using general 2D
interactive graphics. With the mouse and keyboard, the designer fixes vertex positions and
inputs sizes, this creating the polygon. Buttons positions and seam lines are indicated within
the panel polygons. If the designer is not satisfied with his work, he can modify his design in
the same way.
3.3. LAYOUT OF GARMENT PANELS
In the garment industry, most garment panels are not ruled polygons, the cloth fabric usually
is rectangular and it comes in certain sizes only. It is important that the panels be laid out
correctly on the rectangular fabric, otherwise much fabric will be wasted in the large-batch
manufacturing of the garment. To optimize the layout of the panels, a simulated annealing
algorithm [8] is used. First, all the panels are placed on the rectangular fabric arbitrarily, and
the intersections of panel polygons are tested. If some polygons are overlap, they are moved
apart; if the gaps between polygons are too large, they are moved closer. The testing and
moving continues until the necessary length of fabric is obtained, without any superposition
of panels is minimized.
At this point, we also decide which panel edges will be seamed together , and which edges will
be attached to the actor's body.
For example, consider the geometric design of a T-shirt (Fig.2) and pants (Fig.3). The T-shirt
and pants are very simple so each of them could be regarded as a single panel. As shown by
Fig.2, the T-shirt is designed in a 2D rectangular mesh cloth ABCD by specifying the
polygon's vertices v1,v2,v3, ...,v28. It is also specified that the edge v1v28 will be attached to
the waist of the actor, and the edge v5v6 will be seamed with the edge v24v23, the edge
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v11v12 will be seamed to v18v17, and the edge v5v6 seamed to v28v27. All the information,
such as edge numbers of the polygon, the coordinates of vertices, which edge will be seamed
and attached, etc. are stored in the data structure of the panel. The 2D polygonal cloth panel
will be transferred into 3D polygonal panel in ruled surfaces.
4. THE DEFORMABLE CLOTH MODEL AND ITS PARAMETERS
To simulate the sewing and animation of the garment, deformable cloth models must be used.
Physically-based models are preferable in the hopes of increased realism. This should take
into account such physical properties as mass, stiffness, damping factors, inhomogeneity,
anisotropy and viscoelasticity. The model should be deformable under external forces and its
own internal elastic energy, should detect collisions of the cloth with itself and with external
objects, and should be able to create constraint forces when collisions occur. With this model,
diverse kinds of clothing can be created and animated by defining and adjusting the geometric
sizes, the physical properties of cloth and the external forces applied to it. After some
comparisons [7], Terzopoulos' elastic surface model [9] was chosen for our system. In this
model, the main parameters are as follows:
• mass density of the nodal point of the fabric.• damping density of the fabric.• stretching coefficients of the fabric.• bending coefficients of the fabric.• gravity.• external forces, including wind force, collision forces, etc.
• time step for calculating the deformation.
• number of relaxation steps.
These parameters are determined by the physical properties of the fabric. Different fabrics
have different physical properties. For example, silk is hard to stretch but easy to bend,
woolen cloth is more massive and rigid. When worn on the human body, garments with the
same polygonal panels but different fabrics will take on different shapes. The environmental
factors, such as gravity, wind forces, and collision forces also affect the shapes of the
garments, and they can be changed dynamically to examine the garment under various
environments.
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The most useful parameters for modifying the appearance of the motion are the density, the
damping factor, resistance coefficients, the wind and the time interval.
5. SEWING GARMENT PANELS IN THREE DIMENSIONS
Once the desired panels are designed, they are sewn along the indicated seam lines around the
mannequin's body in 3D making use of deformable cloth model. At this stage, the mannequin's
body is static in a standing posture, and gravity is the single environmental factor. The
garment panels are first placed around the mannequin's body, then external sewing forces are
applied to the indicated seam lines shown on the panels. These sewing forces gradually
deform relaxation step and time step. Collisions among the different parts of the garment are
detected and repulsive forces are applied between any two parts of the garment in contact.
When the panels are close enough to the mannequin's body, a collision between the garment
and the body will occur. The body creates the repulsive forces to beep the garment outside
the body [5]. Spring forces are used to simulate the repulsive force. When the seam lines are
all sewn up and the deformation of the garment is complete, the 3D garment has been created
(Fig.4). Some special features of garment, such as wrinkles (Fig.5), folds, and drapes, are
automatically calculated and formed by the deformable cloth model. Texture mapping can
also be applied to the garment, so that it will look more realistic as shown in Fig.6.
For example, as shown in Figure 7, we create a T-shirt and pants in the 2D plane and transfer
them into 3D space around Elvis' body. During the seaming and attachment procedure, the
edges of both the T-shirt and the pants near the body's waist are attached to the waist, the
four edges of the T-shirt near the shoulders are seamed together, and the two bottom edges of
the pants are seamed to each other. As the result, a suit of clothes including article 1, the T-
shirt, and article 2, the pants, has been designed and fabricated. Fig.8 and Fig.9 shows
examples.
In the same way, Fig. 10 shows a dress and Fig. 11 shows a view of Marilyn wearing this
dress.
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6. GARMENT ANIMATION WITH HUMAN BODY MOVEMENT
Garment animation during human body movement is performed by the deformable cloth
model and the human body model. First, a series of sequences of human body movement,
such as walking (Fig.12), running, dancing, jumping, fashion modelling etc. are generated by
the human body model. When the mannequin is moving, collisions between different parts of
the garment itself, and between the garment and the body are tested and repulsive forces are
automatically calculated and applied. Environmental factors, such as gravity, variable wind
forces, air viscosity, are added to deformable cloth model. The sewing forces assure that the
panels remain joined together. With the movement of the body, the shape of the garment,
including wrinkles, folds, drapes, is changed automatically. The parameters of both the fabric
and the environment, can be adjusted flexibly.
7. GARMENT EXAMINATION AND CHANGE
During the procedures of sewing and animation of the garment, the designer checks the
appearance of the garment in three dimensions. If the result is not satisfactory, he can
interactively modify the shapes of panels, or the parameters corresponding to the fabric's
properties, as well as the factors of the environment. The animation is repeated and the
whole process is iterated until the desired effect is obtained.
8. IMPLEMENTATION
8.1 Data structures
At the present stage of development of the garment design tool system, the human body
model and deformable cloth model have both been completed. The 2D interactive design
interface for the garment panel and the template library are still under development.
The clothes on the actor's body may include several articles, such as T-shirts, pants, jackets
and trousers, and each article may consist of several cloth panels, so the data structure of
clothes in the software is hierarchical, as shown in Figure 13.
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In this cloth data structure, the seaming information between panels or within the panel itself,
and the information about attaching each article to actor's body is also included.
The panel is the elementary unit treated by the elastic surface model. In a panel data structure,
there are geometric data and physical data, seaming information and attaching information, as
shown in Figure 14.
The geometric data about a panel include the polygons' edge numbers, the polygons' vertices,
the number of points in the mesh panel, the center of the panel and its rotating angle, etc.
From the geometric data on a panel, we can derive its shape, size, position, normal, and so on.
The physical data on a panel include its mass, the damping factor, speed, forces on it, the
stretch factor, the curvature factor, elastic energies (the stretch energy and curvature energy),
etc..
The seaming information for one panel concerns which edges of the panel should be seamed
together. It includes the number of nodes on the edges and the coordinates of the nodes in the
2D mesh plane, and indicates which node is seamed to which.
The attachment information indicates which edges of the panel are attached to specific points
on the actor's body. It includes the number of nodes on the edges and the coordinates of the
nodes in the 2D mesh plane, and indication of which one node is seamed with which point on
the actor's body.
An article of clothing consists of several panels seamed together, so its data structure contains
the panel data and the information about seaming the panels, together, shown in Figure 15.
The texture mapping approach is also being worked out. For the moment, WAVEFRONT
software is used to put the texture pattern on the garment.
8.2 Collision detection
When we consider collisions between the cloth and the body, we have a situation of actor-
environment interface using a physical motion control method. Collision detection adds extra
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constraints and requires a specific algorithm. For very flexible objects like clothes, it is
necessary to introduce a self-detection. In our method [5], collision avoidance consists of
creating a very thin force field around the obstacle surface to avoid collisions. This force field
acts like a shield rejecting the points. The collision detection process is almost automatic. The
animator has only to provide the list of obstacles to the system and indicate whether they are
moving or not. For a walking synthetic actor, moving legs are of course considered as a moving
obstacle. A number of parameters have been planned in order to modify the behavior of the
collision detection method: shield depth, shield force and damping factor.
As the algorithm speed depends on the number of obstacle polygons, it is prudent to take into
account only polygons which are likely to intersect the cloth. For the example of Marilyn's
skirt, only the pelvis and the legs are considered (Figure 16-17).
With this method, we created and animated flags in the wind and a skirt (Fig.18) in the
computer-generated film Flashback (Fig.19-20).
8.3 Methodology of use
To use this new tool in garment design, the procedure consists of the following steps:
1. Take the measurements of the human body.
2. Interactively draw the polygonal patterns of the garment panels or select the templates
from the garment template library.
3. Modify the shapes of the garment panels.
4. With the deformable cloth model and the human body model, create the garment on the
mannequin body in three dimensions.
5. Simulate and animate the changing shape of the garment with moving sequences of the
mannequin's body.
6. Examine the changing shape of the garment to see if it is satisfactory or not.
7. If the garment is not satisfactory, do (3) to (6) again.
8. Save the patterns in the garment template library.
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9. Draw the patterns of the garment panels on paper.
The above steps illustrate the superiority of this tool over the traditional design approach.
The designer can dynamically visualize his design before the garment is actually made. Much
time and cloth can therefore be saved.
9. CONCLUSION
Using new animation techniques, we are developing a high-tech CAD tool for garment design.
This tool not only designs garment panels in 2D, but it also allows the visual examination of
the garment in 3D on a moving human body with cloth animation, before the garment is
actually manufactured. This improves on traditional garment design which is only carried out
in two dimensions, and makes the design process more convenient and economical.
Acknowledgements
The research is partly supported by the Fonds National Suisse de la Recherche Scientifique, le
fonds FCAR du Québec and the Natural Sciences and Engineering Research of Canada. The
authors would like to thank Arghyro Paouri for the design of several pictures.
References
1. Aono M (1990), A Winkle propagation Model for Cloth, Computer Graphics Interface,
springer 90, Singapore, pp.96-115
2. Hinds BK, McCartney J (1990) Interactive garment design, The Visual Computer, 6,
pp.53-61
3. Platt JC, Barr AH(1988) Constraints Methods for Flexible Models, Proc.
SIGGRAPH'88, Computer Graphics, Vol.23, No.3, pp.21-30
4. Kunii TL, Gotoda H (1990) Modeling and Animation of Garment Wrinkle Formation
Processes, Proc. Computer Animation'90, Springer, Tokyo, pp.131-147
5. Lafleur B, Magnenat Thalmann N, Thalmann D (1991) Cloth Animation with Self-
Collision Detection, in: Modeling in Computer Graphics, edited by TL Kunii, Springer-
Verlag, Tokyo, pp.179-188
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6. Magnenat Thalmann N, Yang Y (1991) Techniques for Cloth Animation, in: New Trends
in Animation and Visualization, edited by N. Thalmann and D. Thalmann, by John
Wiley & Sons Ltd., pp.243-256.
7. Magnenat Thalmann N, Yang Y, Thalmann D (1991) The Problematics of Cloth
Animation", Proc. of 2nd Conference on CAD/CG, International Academic Publishers,
Beijing, China, pp.1-7.
8. Mangen A, Lasudry N (1991) Search for the Intersection Polygon of any Two Polygons:
Application to the Garment Industry, Computer Graphics Forum 10, pp.19-208
9. Terzopoulos D, Platt J, Barr A, Fleischer K (1987) Elastically Deformation Models, Proc.
SIGGRAPH'87, Computer Graphics, Vol. 21, No.4, pp.205-214
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Output Interfaceof Design
2D Design Interface
Garment Templatelibrary
3D Examination
3D Human Body Model
3D DeformableCloth Model
0 5 10 4015 20 25 30 35A
BC
DV1
V2V3
V4
V5 V6
V7
V8 V9
V10
V11 V12
V13
V14 V15
V16
V17 V18
V19
V20
V21
V22
V23 V24
V25
V26 V275
10
15
20
V28
V4
14
0 5 10 4015 20 25 30 35A
B C
DV1
V2
V3
V4 V5
V6V9
V10 V11
V12V13
V1445 50
5
10
15
20
V8V7
A suit of clothes
article 1
article 2
... article m
panel 1panel 2
... panel n1
point 1
point 2
... point k1
panel 1panel 2
... panel n3
panel 1panel 2
... panel n2
15
panel
geometric data: polygon's edge numbers,polygon's vertices, mesh nodes' positions,...
physical data: mass, damping factor, speeds, forces, stretch factor, curvature factor,...
seaming information: edge x1 seamed with edge x2, edge x3 seamed with edge x4,...
attaching information: edge y1 attached to edge z1 on the body, edge y2
attached to points z2 on the body,....
article
panel data: number of panels,series of panels
seaming: edge x1 of y1 seamed with edgex2 of panel y2, edge x3 of panel y3 seamed
with edge x4 of panel y4, ...
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Figure captions
Fig.1. Structure and relationships of the system
Fig.2. Geometric Design of T-shirt
Fig.3. Geometric Design of Pants
Fig.4 An example of 3D cloth
Fig.5 Cloth with wrinkles
Fig.6 Texture mapping
Fig.7 Seaming clothes and putting them on Elvis
Fig.8 Putting a pant on Marilyn
Fig.9 Marilyn wearing a T-shirt and a pant
Fig.10 A dress for Marilyn
Fig.11 Marilyn wearing a dress
Fig.12 Clothes animation in Marilyn's walking sequence
Fig.13. The hierarchical data structure of clothes
Fig.14. The data structure of a panel
Fig.15. The data structure of an article
Fig.16 a-b Skirt animation
Fig.17. A scene from the film Flashback
Fig.18. A scene from the film Flashback
Fig.19. A scene from the film Flashback
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Ying Yang is a PhD student at MIRALab, University of Geneva. He received his MSc inCAD/CAM from Beijing University of Aeronautics and Astronautics. His research interestsinclude three-dimensional computer animation and geometric modeling.E-mail: [email protected]
Nadia Magnenat Thalmann is currently full Professor of Computer Science at theUniversity of Geneva, Switzerland and Adjunct Professor at HEC Montreal, Canada. She hasserved on a variety of government advisory boards and program committees in Canada. Shehas received several awards, including the 1985 Communications Award from the Governmentof Quebec. In May 1987, she was nominated woman of the year in sciences by the Montrealcommunity. Dr. Magnenat Thalmann received a BS in psychology, an MS in biochemistry,and a Ph.D in quantum chemistry and computer graphics from the University of Geneva. Shehas written and edited several books and research papers in image synthesis and computeranimation and was codirector of the computer-generated films Dream Flight, Eglantine,Rendez-vous à Montréal, Galaxy Sweetheart, IAD and Flashback. She served as chairpersonof Graphics Interface '85, CGI '88, Computer Animation '89 and Computer Animation '90.E-mail: [email protected]
Daniel Thalmann is currently full Professor and Director of the Computer GraphicsLaboratory at the Swiss Federal Institute of Technology in Lausanne, Switzerland. Since1977, he was Professor at the University of Montreal and codirector of the MIRALabresearch laboratory. He received his diploma in nuclear physics and Ph.D in ComputerScience from the University of Geneva. He is coeditor-in-chief of the Journal of Visualizationand Computer Animation, member of the editorial board of the Visual Computer and cochairsthe EUROGRAPHICS Working Group on Computer Simulation and Animation. DanielThalmann's research interests include 3D computer animation, image synthesis, and scientificvisualization. He has published more than 100 papers in these areas and is coauthor of severalbooks including: Computer Animation: Theory and Practice and Image Synthesis: Theory andPractice. He is also codirector of several computer-generated films.E-mail: [email protected]