[Radiance-general] Color reflectance values and materials..

[David Smith]

Mark,

That's where gamma values come in. Let's say the RGB values of a paint
sample from EasyRGB are (125,150,175), a blue gray. Take each channel,
divide by 256, take the result to the power of 2.2 (monitor gamma) and
then multiply by 256.

R = (125/256)^2.2 * 256 = 52.9
G = (150/256)^2.2 * 256 = 79.0
B = (175/256)^2.2 * 256 = 110.9

If you put the resulting values (52.9,79.0,110.9) in as the R G and B
material colors, you should get the correct paint color in your
simulation that matches the physical paint color.

--Dave