Am 05.05.2011 14:54, schrieb scottb613:
> Hi Folks,
>
>      I've used POV-Ray for a while - but - I'm still very much a beginner... I'm
> more of a modeler... I stumbled upon some settings I like and I just repeat them
> over and over again while changing the camera location... I recently upgraded my
> POV-Ray from 3.6 to 3.7... When I do my renders of 3DCanvas/Crafter models - the
> colors now seem all washed out... I'm even running old vesrions of POV-Ray files
> that I saved under 3.6 - and the - colors are totally different between the two
> render engines... Is there any trick to make the colors more vivid as they
> appeared in 3.6 ??? Any help - greatly appreciated...

Your old scenes probably have neither a "#version" nor an 
"assumed_gamma" statement. In that case, adding

     #version 3.6;

and/or

     global_settings { assumed_gamma 2.2 }

as the very first statements in your scene file should be the easiest 
way do the job.

If you're still experiencing problems and happen to be rendering to PNG 
file output, try any other output file format (e.g. BMP or TGA).



For background information, see the documentation section about Gamma 
handling already mentioned by Thomas.

In a nutshell, the problem is that up to version 3.5 (and by default 
also in 3.6), POV-Ray used a poorly defined (and inconsistent) color 
model, leading to images that you'd have to call either physically 
inaccurate or overly vivid (depending on how you'd interpret that color 
model); accordingly, scene authors' way of dealing with this situation 
would have to be interpreted as either accepting the physical 
inaccuracy, or using washed-out colors to compensate for the effect.

POV-Ray 3.7's default color model is much more well-defined, and most 
importantly self-consistent; as it is based on the latter 
interpretation, but without giving /overly/ vivid results, old scenes 
will appear to /lack/ vividness.

The workaround of using "#version 3.6;" informs POV-Ray what version the 
scene is designed to render weill with, causing POV-Ray 3.7 to use the 
same color model default as 3.6. Using "assumed_gamma 2.2" explicitly 
tells POV-Ray to use the old color model. Only one of these two 
statements should be necessary, but it won't hurt to use both.



Note that for new scenes it is recommended to instead use

     #version 3.7;
     global_settings { assumed_gamma 1.0 }

(causing POV-Ray to use the new, physically accurate and consistent 
color model), and simply use more vivid material colors instead, as this 
will allow for more realistic results.

Most color pickers will tell you that the less vivid material colors 
should be right; this is because they actually use a different color 
model. To use such color values, instead of (e.g.)

     color rgb <0.6, 0.5, 0.3>

you'll have to use

     color srgb <0.6, 0.5, 0.3>

which is roughly equivalent to

     color rgb <0.33, 0.22, 0.07>

Post a reply to this message