Radiosity problems

I made a radiosity processor for lighting my scenes. The thing works a bit, there are a few problems: - Mapping illumination to [0..1] intensity This proved to be quite hard. A linear mapping operator doesn''t work well. I did find some papers about how to map the illumination to screen colors, but they all assume that I have rendered a view. I want to use radiosity for lightmap calculation. Anybody any ideas? - Placement of the hemicube center on a triangular patch I use triangular patches in the system, but somehow it is difficult to place the hemicube center on it. Currently I just use the triangle''s center-of-mass. (sum(vertex coords)/NrVertices) Using this as the center can give strange results like light sources that appear to be shifted etcetera. Currently I solve this by subdividing the patches, which increases processing time. Is there a better way to solve this? Hmm, enough for now, DaBit.