Lumo : Illumination for Cel Animation
Author(s): Scott F. Johnston.
Proceedings: 2nd International Symposium on Non-Photorealistic Animation and Rendering (NPAR'02), pp. 45--52, Annecy, France, 
2002. 
[BibTeX] 

Abstract: 
A method is presented to approximate lighting on 2D drawings. The specific problem solved is the incorporation of 2D cel animation into live-action scenes, augmenting the existing method of drawn "rims and tones" with subtle environmental illumination. The image-based tools developed to solve the problem have both photorealistic and non-photorealistic applications.