[Jakakadave]

And anyone else who fancies a crack at it.

I have no clue about how to even start on this material. It's called crystal opal and is in its ideal state totally colourless but then has opalescent flashes visible through it, so when you move it about you get flashes of green, blue, red, purple etc.





So KurtS you feel like addidng this to your material lab?

[Fernando Tella]

If you know the Nd or complex ior file it should be easy with dispersion on. Watch out, it increases render time a lot.

[KurtS]

I know close to nothing about gemstones, but I know there are several experts on this matter on this forum. Fernando's advice gives you a great start for trying! but thanks for asking!

[Bubbaloo]

Diamond ior

[Jakakadave]

Yeah - it's very different to diamond. Diamonds sparkle with refracted colours, whereas opals are very different and the areas that have colour are always in the same place even if not always visible, dependant upon lighting conditions, if that makes sense.

I dont think it would be an IOR thing - though certainly that would be important, it's a matter of having several layers of different transparent colours within the middle of the material.

[Fernando Tella]

I don't know if this would be helpful but it I remembered it as I read your post:

http://mxmgallery.maxwellrender.com/sea ... ch=rainbow

[Mattia Sullini]

I fear we couldn't realize this. As far as i have understood concerning maxwell, volume is considered to be homogeneous (same ior...). That iridescence is caused by the microcrystalline structure of the material, making it impossible to simulate in maxwell.
I remember a similar topic regarding dichroic materials...