Henry Fuchs Jack Goldfeather Jeff P. Hultquist Susan Spach John D. Austin Frederick P. Brooks Jr. John G. Eyles John Poulton Fast spheres, shadows, textures, transparencies, and imgage enhancements in pixel-planes. 111-120 1985 conf/siggraph/1985 SIGGRAPH http://doi.acm.org/10.1145/325334.325205 db/conf/siggraph/siggraph1985.html#FuchsGHSABEP85