caustics

[KrisR]

I'm having some problems getting a nice looking caustic effect with a typical wine glass setup. I'm looking for something that gives nice sharp caustics like this:

http://www2.imm.dtu.dk/~jab/gallery/cognac.jpg (http://www2.imm.dtu.dk/%7Ejab/gallery/cognac.jpg)

http://img150.imageshack.us/img150/8425/causticsaq0.jpg

But all I'm getting are fuzzy glowing areas under the glass...where the base meets the floor. The "red" area being cast on the floor from the red wine is not giving any sort of sharp caustic effect nor is the glass itself. Is there any specific setup, shader or geometry needed to create this effect? Does MR just suck at this? :-)

[wurp]

mr uses photons for caustics, the more of them you use the sharper your result will be. Make sure you use spotlights to focus the photons to the important areas, and increase the number of photons if that doesn't help.

[KrisR]

Thanks. I'm getting better results now with 1 million or more photons but its still not anything like those images.

[addi]

try the L-glass shader, crank the intensity energy value on the main spot light up, you could also try fiddling around with the glass geometry make it thicker/thinner
I´ve been able to make fairly nice glass/caustics effects in xsi

.a

[KrisR]

I'm running 64bit and don't have a 64bit version of L-glass. I am however now using the 64bit "True Glass" shader which produces much better results. Default shaders and even the architectural shader are awful at caustics.

[GeneCrucean]

Keep in mind Kris that the actual model plays a huuuge role in caustics.

It will be impossible to match that exact caustic pattern from a completely different object.

[KrisR]

No I know. Its a typical red wine glass shape...with thickness modeled in. The "true glass" is giving much better results now. Just wish there was a realistic glass shader built in to XSI since defaults and architectural do not work as expected.

[eternal art]

Just wish there was a realistic glass shader built in to XSI since defaults and architectural do not work as expected.
Arch materials must give you a nice caustics ... but be sure to turn on the (Enable Refractive Caustics ) it's off by default ...
this is a fast test with 200000 photons ...

http://img231.imageshack.us/img231/7779/causticsqu3.jpg

[KrisR]

Thanks...yes..I realized later yesterday that I didn't have that on....DOH!