Am 13.03.2017 um 22:25 schrieb muyu:
> clipka <ano### [at] anonymousorg> wrote:
>> Am 13.03.2017 um 11:57 schrieb muyu:
>>> Hi,
>>>
>>> I would like to simulate the radiative transfer in 3D crop canopy using Pov-ray.
                   ^^^^^^^^^^
...
> //-----------------------------------------------------------------------------
> #include "colors.inc"
> light_source{<0,0,100> color rgb<1,1,1> parallel}
> 
> #version 3.7; // 3.6;
> global_settings {
>    assumed_gamma 2.2
                  ^^^^^

There are two things in this world that absolutely positively do NOT go
together: The word "simulate" and the POV-Ray setting `assumed_gamma 2.2`.

If physical accuracy is of /any/ relevance to what you are trying to do,
then `assumed_gamma 1.0` is a MUST.


Also, beware that most output file formats by default do _not_ represent
brightness in a linear fashion. For instance, a colour value of
(R,G,B)=(51,51,51) in an output image typically does _not_ represent a
luminance of 20% (51/255), but rather a luminance somewhere around a
meager 3% (approximately (51/255)^2.2).

If you want raw output image data to represent luminance in a linear
fashion, use `File_Gamma=1.0` in the .ini file.

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