Thanks. I'll give it a try. I looked up some of the things you mentioned. It's interesting that an equation can be made to predict the path of photons the eye would encounter in an area, to create realistic light and shadows. Would you recommend some books, or websites I could learn more about raytracing, ambient occlusion, and sub-surface scattering from? I only have a rudimentary idea of how they work, but would like to know enough to be able to work with them without guess work.