I don't remember if this has been discussed before, but the new gamma
handling might cause headaches when using color maps and other interpolated
maps. For example, consider this scene:

//global_settings { assumed_gamma 2.2 }
camera { location -z*4 look_at 0 angle 35 }
plane
{ -z,0
  pigment
  { spherical color_map
    { [0 rgb 0]
      [1 rgb 1]
    }
  }
  finish { ambient 1 }
}

  Render it with pov3.7 without and with the assumed_gamma, and you'll see
the clear difference. Even though the mid-gray might technically speaking
be a truly 50% gray, the gradient doesn't still look linear (what is
supposed to be a smooth gradient fading linearly from white in the center
to black in the border looks almost like a sphere).

  The problem is that if one wants to replicate the "non-gamma-corrected"
look of pov3.6 with this specific pigment, there is no way, other than
making the entire scene assume gamma 2.2, which will then affect *all*
colors. You can't insert a "gamma 2.2" anywhere in that color map to make
it work. (And adding "[0.5 rgb 0.5 gamma 2.2]" will obviously not work.
Try it if you want, without the assumed_gamma.)

  I fear that most people will simply learn to always write the magical
line "global_settings { assumed_gamma 2.2 }" at the beginning of every
scene (or whatever will end up being the proper way in the final version),
making the whole gamma correction thing rather moot.

-- 
                                                          - Warp

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