1. Sketching garments for virtual characters
Sketch-Based Interfaces and Modeling 2004
Sketching garments for virtual characters
Emmanuel Turquin
GRAVIR
Marie-Paule Cani
GRAVIR
John F. Hughes
Brown University
Grenoble, France
Grenoble, France
Providence, USA

2. Outline
Introduction
Contributions
Results
Conclusion

3. Motivations Omnipresence of virtual characters
© 2003 EIDOS
© 2004 PDI/Dreamworks
Video games
Feature films
Cloth modeling still a difficult and tedious task

4. Related work and inspiration
Cloth
modeling

5. Cloth modeling Existing systems: Takes hours…
2D D [Hinds and McCartney 90, Werner et al. 93] (+ plugins for 3D suites)
3D D D [Cugini et al. 99, Bonte et al. 02]

6. Related work and inspiration
Cloth
modeling
Fashion
Design

7. Fashion design
The designer’s way:
Our work

8. Related work and inspiration
Cloth
modeling
Fashion
Design
Sketch-based
interfaces

9. Sketch-based interfaces for 3D modeling
Drawing: an intuitive way of expression
Existing systems
Restricted to volumetric objects: Teddy [Igarashi et al. 99]
Multi-views sketches: [Bourguignon et al. 01]
Sketching + cloth modeling ?
Positioning flat patterns: [Igarashi & Hughes 03]
No 3D sketch-based technique
creating open surfaces

10. Related work and inspiration
Cloth
modeling
Our Work
Fashion
Design
Sketch-based
interfaces

11. Sketching interface for garment design
Takes few minutes…
Sketching interface for garment design

12. Problems to address Intuitive creation process Identifying elements of
the drawing
Inferring the
third dimension

13. Outline
Introduction
Contributions
Results
Conclusion

14. Contributions Intuitive creation process Identifying elements of
the drawing
Inferring the
third dimension

15. Intuitive creation process: what kind of drawing ?
Shaded drawing: + A lot of information - For a computer, difficult to interpret -- For a human, difficult to draw
Line drawing: - Less information + Easier to interpret ++ Easier to draw

16. Intuitive creation process: what kind of drawing ?
Views: front (and back), like fashion design
Posture:
Try to avoid overlapping
Rather use a « T » stance

17. Intuitive creation process
No cloth templates: be generic
Avoid distracting movements
No change of tools: only paper and a pen
Iterative creation process: constant visual feedback

18. Presentation of our method
2D Treatment
Pretreatment
3D Treatment

19. Presentation of our method
Pretreatment
Body mask
Load 3D model

20. Presentation of our method
2D Treatment
Pretreatment
Load 3D model

21. Presentation of our method
2D Treatment
Body mask

22. Contributions Intuitive creation process Identifying elements of
the drawing
Inferring the
third dimension

23. Identifying elements of the drawing
Kinds of lines:
Contours /
Silhouettes /
Borders /
Folds /
Seaming lines /
Others…
For now on: only silhouettes and borders

24. Presentation of our method
2D Treatment
Body mask
Closed curve,
with the types
of strokes

25. Contributions Intuitive creation process Identifying elements of
the drawing
Inferring the
third dimension

26. Inferring the third dimension
Under-constrained problem We have to choose a (default) solution
Examples: or

27. Inferring the third dimension
Under-constrained problem We have to choose a (default) solution
Examples: or

28. Inferring the third dimension
Under-constrained problem Choose a (default) solution
Propagate the distance information from the contour to the body, all over the garment
Speed-up distance queries by using a distance field

29. Presentation of our method
Pretreatment
Body mask
Load 3D model
Distance field

30. Presentation of our method
2D Treatment
Pretreatment
Load 3D model
3D Treatment

31. Presentation of our method
3D Treatment
1/ Strokes: For all P:
distance to the body: P.dist
depth value: P.z
Closed curve,
with the types
of strokes
Distance field

32. Presentation of our method
3D Treatment
1/ Strokes: OK
2/ Surface:
Create buffer
Determine the inside/outside
Propagate the distance values inside the buffer
For each (x,y) of the inside region, find depth
Mimick cloth tension
Closed curve,
with the types
of strokes
Distance field

33. Mimicking cloth tension
Before :
After :

34. Presentation of our method
3D Treatment
1/ Strokes: OK
2/ Surface:
Create buffer
Determine the inside/outside
Propagate the distance values inside the buffer
For each (x,y) of the inside region, find depth
Mimick cloth tension
Smooth the garment
Tesselate the garment
Closed curve,
with the types
of strokes
Distance field

35. Presentation of our method
3D Treatment
1/ Strokes: OK
2/ Surface: OK
Closed curve,
with the types
of strokes
Resulting
surface
Distance field

36. Presentation of our method
2D Treatment
Pretreatment
Load 3D model
3D Treatment
Result

37. Outline
Introduction
Contributions
Results
Conclusion

38. Results

39. Results

40. Results

41. Results

42. Results

43. Results

44. Outline
Introduction
Contributions
Results
Conclusion

45. Discussion
First method for dressing virtual characters from 2D sketches of their garments
Fast and easy
But:
Only the front part
Garments do not look extremely realistic

46. Future Work Generate a full garment, from front and back views
Add expressivity: let user alter default behavior of the system
Manage folds and seaming lines
Take physics into account (gravity, materials, …)
Flatten the 3D surface into patterns
User study

47. Thanks for your attention.
Any questions?