POV-Ray : Newsgroups : povray.advanced-users : lightsys and gamma : Re: lightsys and gamma Server Time
25 Jun 2024 22:53:35 EDT (-0400)
  Re: lightsys and gamma  
From: Alain
Date: 21 Jun 2011 22:13:39
Message: <4e014fd3@news.povray.org>

> Jaime Vives Piqueres<jai### [at] ignoranciaorg>  wrote:
>>     AFAIK, no... in fact, it was designed to be used with
>> assumed_gamma=1.0. In general, the only change needed for 3.7 is to
>> adapt the default skydome finish to use "emission" instead "ambient",
>> but that can be already done by declaring "fiLuminous" before calling
>> the include.
>>
>>     Regards,
>>
>> --
>> Jaime Vives Piqueres
>>
>> La Persistencia de la Ignorancia
>> http://www.ignorancia.org
>
> Yes, but on Windows at least the default output in 3.7 is closer to
> assumed_gamma=2.2, thus some modification is needed, yes?
>
>
> Mike
>
>

For the display, it's "display_gamma" from the main ini file. It only 
affect how the image is displayed in the preview.
For the output file, at least with PNG, it's "file_gamma". For a PNG 
file, it set the gamma chunk of the file. For other formats that don't 
support that, it adjust the data in the file.
display_gamma and file_gamma sould normaly have the same value.

It seems that, if they are not explicitely set, they default to 2.2.

BUT, as the computation is performed, it should be assumed_gamma 1 to 
use a linear colour space.


Alain


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