color map lighting

[Jim Bennett]

In article <9104201746.AA07556 at karron.med.nyu.edu> karron at cmcl2.nyu.edu writes:
>
>The gl prog guide says that color map lighting has some
>inherent limitations.
>
>What are they ?

The main limitation is that you are limited in the number of colors
you can use.  For each color, you have to provide a color ramp that
that the lighting calculations can index into.

Another limitation is that the color ramp has to include the color
of the light as well as the color of the object.  So you can't
get a scene with two different colored light sources in color
index mode.

>Color map lighting  advanced features are not supported. Color map
>recognizes a limited set of properties.
>
>Why ?

Many of the properties don't apply in color index mode.  After all,
in color index mode, the lighting calculations have to come down to
a single index into a color ramp.

>Which is the better way to go: rgb or color map for lighting models in
>the long run ?

RGB is the way to go.

>Cheers!
>
>dan.
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Jim Bennett				(bennett at sgi.com)