“Texture mapping for cel animation” by Correa, Jensen, Thayer and Finkelstein

We present a method for applying complex textures to hand-drawn characters in cel animation. The method correlates features in a simple, textured, 3-D model with features on a hand-drawn figure, and then distorts the model to conform to the hand-drawn artwork. The process uses two new algorithms: a silhouette detection scheme and a depth-preserving warp. The silhouette detection algorithm is simple and efficient, and it produces continuous, smooth, visible contours on a 3-D model. The warp distorts the model in only two dimensions to match the artwork from a given camera perspective, yet preserves 3-D effects such as self-occlusion and foreshortening. The entire process allows animators to combine complex textures with hand-drawn artwork, leveraging the strengths of 3-D computer graphics while retaining the expressiveness of traditional hand-drawn cel animation.

1. Kendall E. Atkinson. An Introduction to Numerical Analysis. John Wiley & Sons, New York, 1988.
2. Thaddeus Beier and Shawn Neely. Feature-Based Image Metamorphosis. In Edwin E. Catmull, editor, SIGGRAPH 92 Conference Proceedings, Annual Conference Series, pages 35-42. ACM SIGGRAPH, Addison Wesley, July 1992.
3. Thomas H. Cormen, Charles E. Leiserson, and Ronald L. Rivest. Introduction to Algorithms. MIT Press, Cambridge, Mass., 1990.
4. Cassidy J. Curtis, Sean E. Anderson, Joshua E. Seims, Kurt W. Fleischer, and David H. Salesin. Computer-Generated Watercolor. In Turner Whitted, editor, SIGGRAPH 97 Conference Proceedings, Annual Conference Series, pages 421-430. ACM SIGGRAPH, Addison Wesley, August 1997.
5. Gerald Farin. Curves and Sulfaces for Computer Aided Geometric Design: a Practical Guide. Academic Press, 1997.
6. Jean-Daniel Fekete, l~rick Bizouarn, l~ric Cournarie, Thierry Galas, and Fr6d6ric Taillefer. TicTacToon: A Paperless System for Professional 2-D Animation. In Robert Cook, editor, SIGGRAPH 95 Conference Proceedings, Annual Conference Series, pages 79-90. ACM SIGGRAPH, Addison Wesley, August 1995.
7. James D. Foley, Andries van Dam, Steven K. Feiner, and John F. Hughes. Computer Graphics, Principles and Practice. Addison-Wesley, Reading, Massachusetts, second edition, 1990.
8. Michael Gleicher. Image Snapping. In Robert Cook, editor, SIGGRAPH 95 Conference Proceedings, Annual Conference Series, pages 183-190. ACM SIGGRAPH, Addison Wesley, August 1995.
9. Michael Kass, Andrew Witkin, and Demetri Terzopoulos. Snakes: Active Contour Models. International Journal of Computer Vision, pages 321-331, 1988.
10. Seung-Yong Lee, Kyung-Yong Chwa, Sung Yong Shin, and George Wolberg. Image Metamorphosis Using Snakes and Free-Form Deformations. In Robert Cook, editor, SIG- GRAPH 95 Conference Proceedings, Annual Conference Series, pages 439-448. ACM SIGGRAPH, Addison Wesley, August 1995.
11. Apostolos Lerios, Chase D. Garfinkle, and Marc Levoy. Feature-Based Volume Metamorphosis. In Robert Cook, editor, SIGGRAPH 95 Conference Proceedings, Annual Conference Series, pages 449-456. ACM SIGGRAPH, Addison Wesley, August 1995.
12. Peter Litwinowicz. Processing Images and Video for an Impressionist Effect. In Turner Whitted, editor, SIGGRAPH 97 Conference Proceedings, Annual Conference Series, pages 407-414. ACM SIGGRAPH, Addison Wesley, August 1997.
13. Peter Litwinowicz and Lance Williams. Animating Images with Drawings. In Andrew Glassner, editor, SIGGRAPH 94 Conference Proceedings, Annual Conference Series, pages 409-412. ACM SIGGRAPH, Addison Wesley, July 1994.
14. Lee Markosian, Michael A. Kowalski, Samuel J. Trychin, Lubomir D. Bourdev, Daniel Goldstein, and John F. Hughes. Real-time Nonphotorealistic Rendering. In Turner Whitted, editor, SIGGRAPH 97 Conference Proceedings, Annual Conference Series, pages 415-420. ACM SIGGRAPH, Addison Wesley, August 1997.
15. Barbara J. Meier. Painterly Rendering for Animation. In Holly Rushmeier, editor, SIGGRAPH 96 Conference Proceedings, Annual Conference Series, pages 477-484. ACM SIGGRAPH, Addison Wesley, August 1996.
16. Eric N. Mortensen and William A. Barrett. Intelligent Scissors for Image Composition. In Robert Cook, editor, SIGGRAPH 95 Conference Proceedings, Annual Conference Series, pages 191-198. ACM SIGGRAPH, Addison Wesley, August 1995.
17. Michael Plass and Maureen Stone. Curve Fitting with Piecewise Parametric Cubics. In Peter Tanner, editor, SIGGRAPH 83 Conference Proceedings, Annual Conference Series, pages 229-239. ACM SIGGRAPH, July 1983.
18. Barbara Robertson. Disney Lets CAPS out of the Bag. Computer Graphics World, pages 58-64, July 1994.
19. D. F. Rogers and J. A. Adams. Mathematical Elements for Computer Graphics. McGraw-Hill, New York, second edition, 1990.
20. Walter Roberts Sabiston. Extracting 3D Motion from Hand- Drawn Animated Figures. M.Sc. Thesis, Massachusetts Institute of Technology, 1991.
21. Takafumi Saito and Tokiichiro Takahashi. Comprehensible Rendering of 3-D Shapes. In Forest Baskett, editor, SIG- GRAPH 90 Conference Proceedings, Annual Conference Series, pages 197-206. ACM SIGGRAPH, Addison Wesley, August 1990.
22. Philip J. Schneider. An Algorithm for Automatically Fitting Digitized Curves. In Andrew S. Glassner, editor, Graphics Gems, number I, pages 612-626. Academic Press, 1990.
23. Thomas W. Sederberg, Peisheng Gao, Guojin Wang, and Hong Mu. 2D Shape Blending: An Intrinsic Solution to the Vertex Path Problem. In James T. Kajiya, editor, SIGGRAPH 93 Conference Proceedings, Annual Conference Series, pages 15-18. ACM SIGGRAPH, Addison Wesley, August 1993.
24. Thomas W. Sederberg and Scott R. Parry. Free-Form Deformation of Solid Geometric Models. In David C. Evans and Russell J. Athay, editors, SIGGRAPH 86 Conference Proceedings, Annual Conference Series, pages 151-160. ACM SIGGRAPH, August 1986.
25. Michael A. Shantzis. A Model for Efficient and Flexible Image Computing. In Andrew Glassner, editor, SIGGRAPH 94 Conference Proceedings, Annual Conference Series, pages 147-154. ACM SIGGRAPH, Addison Wesley, July 1994.
26. Robert E. Tarjan and Jan van Leeuwen. Worst-Case Analysis of Set Union Algorithms. Journal of the ACM, 31(2):245- 281, April 1984.
27. Frank Thomas and Ollie Johnston. Disney Animation: The Illusion of Life. Walt Disney Productions, New York, 1981.
28. B.A. Wallace. Merging and Transformation of Raster Images for Cartoon Animation. In Henry Fuchs, editor, SIGGRAPH 81 Conference Proceedings, Annual Conference Series, pages 253-262. ACM SIGGRAPH, August 1981.
29. Dan S. Wallach, Sharma Kunapalli, and Michael F. Cohen. Accelerated MPEG Compression of Dynamic Polygonal Scenes. In Andrew Glassner, editor, SIGGRAPH 94 Conference Proceedings, Annual Conference Series, pages 193-197. ACM SIGGRAPH, Addison Wesley, July 1994.
30. Walt Disney Home Video. Aladdin and the King of Thieves. Distributed by Buena Vista Home Video, Dept. CS, Burbank, CA, 91521. Originally released in 1992 as a motion picture.
31. Lance R. Williams. Topological Reconstruction of a Smooth Manifold-Solid from its Occluding Contour. Technical Report 94-04, University of Massachusetts, Amherst, MA, 1994.
32. Georges Winkenbach and David H. Salesin. Computer- Generated Pen-and-Ink Illustration. In Andrew Glassner, editor, SIGGRAPH 94 Conference Proceedings, Annual Conference Series, pages 91-100. ACM SIGGRAPH, Addison Wesley, July 1994.
33. Andrew Witkin and Zoran Popovi& Motion Warping. In Robert Cook, editor, SIGGRAPH 95 Conference Proceedings, Annual Conference Series, pages 105-108. ACM SIG- GRAPH, Addison Wesley, August 1995.
34. George Wolberg. Digital Image Warping. IEEE Computer Society Press, Washington, 1990.
35. Daniel N. Wood, Adam Finkelstein, John F. Hughes, Craig E. Thayer, and David H. Salesin. Multiperspective Panoramas for Cel Animation. In Turner Whitted, editor, SIGGRAPH 97 Conference Proceedings, Annual Conference Series, pages 243-250. ACM SIGGRAPH, Addison Wesley, August 1997.