Is it possible to make a prism, and put a material on it that combined with caustics would turn a white direct light into rainbow light that will be reflected/refracted onto the floor near the prism??? Right now I can get the prism to correctly bend the light where it needs to go, but instead of rainbow reflections I get white ones…
Thanks,
Andrew
It is not possible,well not directly, dispersion is not supported. There is a material by s7en that can do it http://myweb.tiscali.co.uk/elvis/dispersion.htm 
maybe it’s just me, but that link is not working… I’d be very interested to see this material you spoke of.
Sorry, thought I had that copy paste thing figured out 
did something similar a few months ago
by rendering it out with 3 different ior, and comping the appropriate channels back into photoshop.
let me know if you get stuck
and i can elaborate
Cheers for the link to my page Rerender.
ApocGFX, your message prompted my to try out rendering a prism using my dispersion material. Here’s the result:
Seems to work on a basic level, but it doesn’t produce the entire spectrum - it stops at blue, so no indigo or violet.
The material works in a similar manner to Artizen’s technique, except it uses Shellac material to composite the three IOR channel together in Max, rather than comping them in photoshop.
You can down load the max file of this scene/material here:
http://myweb.tiscali.co.uk/elvis/prismtest.zip
Best of luck,
sven
thats a pimpn pic sven, thanks. downloaded
percy
Cheers dude. Enjoy!