working on something…
what do you think?
one thing pops into mind… where can i get it
Looks really nice. Did it take 12min for the actual attached image or is this a resize.?
zoran
have to further test it. i’m trying to compare it to real prism photos, not sure if the spectrum distribution is correct.
yeah, the render time is right for that image. that’s with full brute force GI though, and everything “on”. caustics are heavy. they are either sharp/noisy or blurred altogether, i don’t think i can get them smooth+sharp, as with GI (irradiance map).
looks really interesting 
It is based on the technique of having three different materials with different IOR for rgb? Looks nice in many situations, but in others, like the left part of the image, it gets a little too obvious that there are only three different IORs.
But nice to get a material that does the job of creating the sub-materials for you.
Indeed, it looks like a material encapsulation based on the technique Vlado explained a long while back for three colors.
Unfortunately i had one such tester ready a while back, but
A) I couldn’t implement the full spectrum (well, 7 colors) due to my own ineptitude, and
B) scripted materials didn’t work inside a VRay Blend, making them very nice a concept, but also very limited in that it wasn’t possible to expand on the set of functions.
Could you manage to get around both issues, i’d be overly thankful for the addition!
you’re right…a scripted material won’t work in a blend material…bummer…
didn’t know that…but it’s not crucial, for a gemstone material.
i use 3 color filters. i also tried full spectrum with 7 colors, but it gives me the same result, with longer render time.
i’m not aiming for full tweakability, but for a quick and useable gemstone material.
(still cooking with water of course…blend material)
the spectrum is quite good IMO…could use some jitter in the IOR shift maybe:
^-rendered with 3 filters (rgb), linear IOR shift, slight glossy refraction
^- photo reference,
from this site: Sectrum by Dispersion of White Light passinng through Prism Photographs
Looks Awesome Plastic …
I think it is looking awesome so far, nice work 
This is really good. And yes, it would be very useful, so you don’t have to do the material blending yourself.
this will be the last teasing pic, i promise
i’ll try to get the script finished tomorrow…
Very Good news !!!
Best regards…
Looking very good 
How about a teasing pic with some volumetric caustics? :o
wow amazing.
glad you like it…
i’m working on a kickass preset browsing system, so the release is pushed back to next week.
if anyone wants to play with a pre-release, drop me a PM…
Is it possible to script it in this material so that items/objects with only these materials emit caustics?
It would be a pain to do a manual override on an entire scene with caustics turned on. To be honest, I really don’t use them much because I’m generally afraid of raising rendering times.
well, that can be controlled with the object properties, or with material wrappers.
as far as i see, there is no way to tell an object, that it must be the only one generating caustics.
instead, the other objects have to be excluded from caustics calculation.
but for gemstones caustics aren’t that important, i think. in the last pic, there are no caustics.
i hope the caustics calculation will improve in vray, right now they eat up RAM like crazy. i find it almost impossible to get clean results with area lights. i hope that some day we can render them in a progressive, memory saving way, like the lightcache.
plastic this looks really good and very useful. cant wait to see it finished. And btw, check you PM.