I have been kinda successful with light beams by making a conical mesh,
then assigning a moving random dot opacity map to it. It looks like a smoky
room with dust particles in the light. I haven't perfected it, but my tests
proved the idea worked. I believe there is a lo-res example called
SMOKE.ZIP in COMART, DL17.
Doug,
Morphing an object with a smoke-like opacity map should also be good
for representing dispersion of gases.
Kevin Krell – Computer Support Associates