11-7-04 - 4


It would be fun to work on a 3d engine that's all physically accurate lighting. So far as I know, such a thing has never been done, and is even rarely done in pre-rendered CG. We still can't do realtime radiosity, so we have to hack the rendering equation in various ways. One thing we can simulate quite well now is a semi-static environment, where the radiosity effects are precomputed in various ways and the direct lighting effects are evaluated in real time in various ways. The main flaws with these approaches are that the dynamic objects don't interact with the render equation well, eg. they don't contribute to the radiosity solution correctly, and the less static the world is, the less correct the lighting can be. The biggest thing for physically accurate lighting in 3d hardware is floating point buffers; this lets you capture the massive differences in brightness between lit and unlit areas. You of course then need an exposure function to simulate the aperture of the eye or a camera.

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