At 09:59 AM 11/11/2005 +0000, you wrote: [...]
However, using an HSV colour space throughout the render pipeline might not be too hard. Create a custom HSV channel and in certain shaders do the conversion. Say in Surface Properties for objects, and Light Properties for lights.
Long live the channels again!
There's a definite downside to HSV too though. [.....] This works out as dark mustard yellow!
I see the problem...
Averaging Hue's doesn't work. The Raytracing process would have to become a lot more complex in it's calculations to work out the correct results. At the moment I'm not sure what calculations would do the job. HSV is tricky to work in. V works okay but H can't be averaged at all and S needs to be changed based on what the other two channels are doing, so can't be dealt with linear interpolation. I guess this is why there's no GPU's that work in HSV! I think it'd be quite a breakthrough in rendering quality if someone could get a working HSV raytracing engine. Every time there's overbright areas in a computer generated image the saturation is always wrong in additive RGB. Maybe a solution is a hybrid that uses S and V in illumination, coupled with RGB processing to derive colours? David Coombes
Maybe it's not such a problem that all the internal data processing is RGB... it should help that everything is 64-bit FP precision so no information is lost. Tools like your scripts could help step by step...
thanks for the elaborate mail, Mark H
