Steve Baker (steve++at++mred.bgm.link.com)
Wed, 22 Jan 97 10:48:05 -0500
> Is it possible to get the RGB color value from any place between the two end
> points of a Gouraud shaded line? The line is a pfGeoSet.
Angus Dorbie <dorbie++at++bitch.reading.sgi.com> replied:
> This is a linear interpolation in screen space.
>
> Problems will arise if you want to calculate this for projected
> screen space and the line is in perspective because the colour
> interpolation is not perspective correct. This gets real fun
> when you clip the line because the colour gets shaded from the
> interpolated clipped line end colour.
In fact, it's even worse than that - the colour of some point
on a gouraud shaded line/polygon can be different on different
channels.
Steve Baker 817-619-1361 (Vox-Lab)
Hughes Training Inc. 817-619-8776 (Vox-Office/Vox-Mail)
2200 Arlington Downs Road 817-619-4028 (Fax)
Arlington, Texas. TX 76005-6171 Steve++at++MrEd.bgm.link.com (eMail)
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"You can't destroy the Earth - that's where I keep all my stuff!" - The Tick.
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