Am 09.06.2010 05:57, schrieb SharkD:
> Any general guidelines on converting scenes created before assumed_gamma
> or 3.7 were in wide use to the new defaults?

That's a bit problematic: Before "assumed_gamma 1.0" or the most recent 
3.7 betas, the color math was simply /wrong/. So in order to get exactly 
the same result, you'd have to mimick that wrong color math - which 3.7 
refuses to, except for legacy scenes using "#version 3.6" (or anything 
smaller than 3.7) and "assumed_gamma 2.2".

If you do want to port the scene to the right math, here's what I expect 
to be the most important steps:

(0) In the ini-file, set the "Display_Gamma" to whatever fits your 
system; set "File_Gamma" to the same. (Ideally, your system should have 
a Display_Gamma of 2.2.)

(1) In the scene file, use "#version 3.7", and remove any 
"assumed_gamma" statement.

(2) Gamma-adjust all color literals, by raising the R,G,B components to 
the power of 2.2 (or wait for the next beta, and add "gamma 2.2" to the 
color literal). Check your scene for colour values that are computed 
from some other values - you may (or may not) want to gamma-adjust these 
as well.

(3) Check your scene for input image files, and whether they are handled 
properly regarding gamma. For images that are used as anything non-color 
(e.g. height field data, bump map, texture map or what-have-you), 
explicitly specify "file_gamma 1.0" after the filename (next beta will 
also support "gamma 1.0" here). For any images that do wind up being 
used as a colour, try the default first (i.e. no "file_gamma" 
statement); if the colours appear too washed-out or too strong, try 
explicitly specifying "file_gamma srgb".

(4) Toy around with overall brightness and/or brightness of individual 
light sources, until you feel comfortable with the illumination. You may 
also want to tweak some of the colours in your scene (both pigment and 
light sources). If you're using self-made input image files, you may 
also want to tweak their file_gamma setting, but try to avoid this with 
3rd party input images (you should usually find a way to make them work 
by tweaking the scene rather than the image).

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