[vtkusers] Lighting and washed out colors

[Lisa S. Avila]

Hello Kevin,

If you have "too much" light in your scene (either from light sources or 
caused by your lighting coefficients for a surface adding up to more than 
1.0) then the computed color for a pixel may exceed 1 on some component. 
The color components are independently clamped to 1. Your scalar color may 
be 1.0, 0.1, 0.1 (mostly red) but due to the lighting parameters the shaded 
value may be 5.0, 0.5, 0.5 - which will be displayed as 1.0, 0.5, 0.5 (a 
much more washed out red). Try adjusting your ambient / diffuse / specular 
coefficients so that they do not add up to much more than 1.0.

Lisa


At 07:24 PM 8/15/2002, Kevin Wright wrote:
>Can anyone tell me why, if I have diffuse lighting set to something 
>non-zero, and I turn ambient lighting up to a non-zero number that the 
>colors on my scalar-mapped surfaces start washing out?  Is this something 
>intrinsic in OpenGL Lighting?  Can I work around it?
>
>I would like to keep shading, while also having some ambient lighting for 
>better visibility, but I can't afford to wash out the color mapping.
>
>Any information would be appreciated.
>
>Thanks,
>Kevin.
>
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