clipka <ano### [at] anonymousorg> wrote:
> But I suggest everyone to calm down a bit; There are two approaches to 
> working with colors in POV-Ray: (1) Using assumed_gamma 1.0 for 
> photorealism, and (2) using assumed_gamma 2.2 (or something alike) for 
> more pleasant brightness gradients in color_map and the like. Warp has 
> always been a proponent of the latter, while you and I are proponents of 
> the former, but at present it must be conceded that both have their 
> benefits.

  The major problem I see with assumed_gamma 1.0 is that designing textures
becomes more complicated, because textures are usually designed by how they
should look rather than what their absolute irradiance values are.

  If you are only specifying individual colors, then using 'srgb' takes
care of that. However, patterns present a problem. Usually you want
patterns to interpolate linearly from one color to another (with what
I mean that the interpolation should *look* linear).

  As a simple example, one would expect

    color_map { [0 srgb 0][0.5 srgb 0.5][1 srgb 1] }

to look identical to

    color_map { [0 srgb 0][1 srgb 1] }

  (With assumed_gamma 2.2 it does, but obviously not with assumed_gamma 1.0.)

  The problem is that with assumed_gamma 1.0 the gradient will be linear
in terms of irradiance rather than in terms of perceived brightness.

  I understand that some work will be done to alleviate this problem.
Optimally one should be able to define entire textures with an "assumed
gamma" other than 1.0, which would make those gradients look linear.

  Until that time using assumed_gamma 2.2 is just more convenient in many
cases, even if it technically speaking produces an incorrect rendering.

-- 
                                                          - Warp

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