Abstract

In traditional cel animation, background scenery is painted in high detail, but moving characters are painted with flat colors.

Manually painting moving characters with complex textures is very laborious and leads to inconsistencies between frames.

We present a method to partially automate the application of complex textures to moving characters in cel animation.The idea is to correlate features in the hand-drawn artwork with features in a simple, textured, 3-D model, distort the model to conform to the artwork, and use the rendered model in the place of the flat colors.

The implementation employs a new silhouette detection algorithm and a new depth-preserving warp. The silhouette detector is simple, efficient, and produces smooth, visible contours on a 3-D model. The warp makes the model match the artwork from a given camera perspective, and preserves 3-D effects such as self-occlusion and foreshortening.

Our method requires relatively little effort per frame, and minimizes inconsistencies between frames. Animators can thus use complex textures with hand-drawn artwork, combining the accuracy of 3-D computer graphics with the expressiveness of hand-drawn animation.

Full paper

To learn more about our project, download the full paper in compressed PostScript (3.3M) or PDF (670K). In Michael Cohen, editor, SIGGRAPH 98 Conference Proceedings, Annual Conference Series, pages 435-446. ACM SIGGRAPH, Addison Wesley, July 1998. ISBN 0-89791-999-8.