Jump to content

  • Log In with Google      Sign In   
  • Create Account


#ActualBacterius

Posted 20 September 2012 - 02:02 AM

Update: scaling the RGB values with the total measured radiance and tonemapping that seems to be the right thing to do, anything else produces garbage. For future reference, since I had a hard time "getting it": the absolute per-wavelength radiance in your spectral power distribution is irrelevant in determining the resulting perceived color - all that matters is the relative radiance between wavelengths (the "shape" of the distribution). However, this will only give you the color, which is fundamentally different from what you would think a "color" is because it does not encode luminance information at all - the luminance (shade) is the area under the spectral power curve (e.g. the total radiance over the visible spectrum) and this is where the absolute measurements are used. This will give you a wide luminance range to work with, which you can then tone map at your leisure.

#1Bacterius

Posted 20 September 2012 - 02:01 AM

Update: scaling the RGB values with the total measured radiance and tonemapping that seems to be the right thing to do, anything else produces garbage. For future reference, since I had a hard time "getting it": the absolute per-wavelength radiance in your spectral power distribution is irrelevant in determining the resulting perceived color - all that matters is the relative radiance between wavelengths (the "shape" of the distribution). However, this will only give you the color, which is fundamentally different from what you would think a "color" is because it does not encode luminance information at all - the luminance (shade) is the area under the spectral power curve (e.g. the total radiance over the visible spectrum) and this is where the absolute measurements are used. This will give you a wide luminance range to work with, which you can then tone map at your leisure.

PARTNERS