Diamond & Gem Shader in Maya 8.5

[epq]

The key to any dielectric material is right IOR (index of refraction) and reflections.
Id use mia_material, max the reflection and refraction set the IOR to 2.417 for diamond.

A sassy HDR or a well placed bounce cards would give you nice reflections.

/eric

[moviejunkie101]

I still really haven't been able to get really good renders though...

Does anyone have a dead on shader for a diamond?

[Stahlberg]

Here's my own kooky method, a bit of a fake, but it looks ok and renders fast.

http://forums.cgsociety.org/showthread.php?t=406886

[moviejunkie101]

Thanks... Anyone else have anything?

[Sergio76]

If you want realistic look, the method epq suggested is the way to go (dielectric + HDR or bounce cards).

I still really haven't been able to get really good renders though...
What exactly is the problem you encountered?

You can check "Ignore_normals" option in dielectric material attributes, also you can increase "Phong_coef" value - this option will increase highlights of dielectric material and can also help if you have black areas in render.

This tutorial has lightning and caustics setup for a diamond:
http://www.lemiere.com/tutorials/tutorials_caustics.htm

[Stahlberg]

That tutorial seems to produce results that look great for general gem stones, especially darker ones like rubies... but not so much for diamonds...
http://www.foreverdiamonds.com.au/images/diamond.jpg
I think my method comes quite close to that peculiar bright caleidoscopic diamond look:
http://www.androidblues.com/diamondtest.jpg
Plus it renders much faster. :)

[wat2k]

Stahlberg, Your tricks is superb. I wonder how do you found this method.

Could you tell me the theory and how did you connect a surface to 2 shader groups?

http://www.pic2you.net//iw/wgcap.jpg

[Stahlberg]

Thanks! I came up with this basic type of trick nearly 10 years ago, when renderers were totally unable to create any kind of nice gemstone look. Today, we're almost at the point where the trick isn't needed anymore... sniff. Goodbye faithful friend. :D

2 shaders on the same surface, just select some polygons, apply 1 shader, select the other polygons, apply the other. :)

[moviejunkie101]

What would everyone recommend for the reflection & refraction and other settings for doing gems like an emerald, ruby, etc? I know the IORs for these, just would like to know what I should put for other settings compared to a diamonds reflect & refract settings... Thanks

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