It was so fun, when I first went to grad school Pat, Peter, and I figured out the fundamentals how to separate the lighting from the surface reflection using multi-resolution textures maps. And it was so fun sitting in the Princeton Graphics lab hacking up the Renderman shaders to implement it for the first time. Great memories, and what amazing insights and tools built by so many others to make what we have now possible. :)
Yep. For the radiosity based global illumination things, it's the most common way of framing and solving the way light energy is passed through an environment. And most of the work is in minimizing the computationally expensive visibility operations (shadows, etc) by determining how much light energy is going to pass between two surfaces (based on distance, size, orientation, visibility, etc), and then computing using the fewest rays and the right level of resolution of the energy to efficiently utilize compute resources. Basically... :)
I'm currently working on a cute little rasterizer in JS; a software radiosity engine would be really fun! Would you mind shooting me an email (link in profile) with any links/resources you think might be helpful for a noob?
http://dl.acm.org/citation.cfm?id=192171