Chroma-Keying
Chuck:
It provides a _perfect_ key, every time. I wrote a chapter on it for the
upcoming 3DS Special Effects book for New Riders Publishing.
In a nutshell, just render with either 32 bit Targas or split alpha and
composite with that.
Or take a look at our "Auto-Matt Generator Chroma Key IPAS Routine" (the only
reason it is not yet shipping is that we haven't been able to condense that
down to 6 letters for an IPAS routine! <g>
Greg Pyros