Last week I released a diamond material on my blog. I got a few comments suggesting some changes, so I thought I would go back and tweak some things. So here it is: v2 of the diamond shader. Continue reading to see what I changed and download the shader.
I’ve uploaded the .blend file so you can tweak it.
Here’s how the shader looks with a HDRI:
Here’s how the node group looks like now:
And inside the group:
Unlike the previous version (which had two shaders), I’ve added a dispersion amount, so you only need one shader. However, I kept the Volume Absorption the same. I’ve also added a couple different inputs including: Roughness, IOR, and Dispersion.
After doing some more research (and many formulas later), I resorted to master blendheads before me: the standard red, green, and blue combination. I tried using the wavelength node and some math combinations but the standard combination just works really well. Really, cycles should bend the different wavelengths for us, but that currently doesn’t happen (I would love for it to be implemented, hint, hint 
).
The shader now works by using three glass shaders to simulate the primary colors: red, green, and blue. The dispersion effect still works the same: the IOR is slightly different for each glass shader. Then I combined them with the add shader (which now adds exactly to white).
Here are the correct IORs for different colors passing through diamond: red 2.410, green 2.426, and blue 2.444.
Download the blend here: http://www.blendswap.com/blends/view/77949
Look at more photos and read how to use it here: https://neuinspiration.wordpress.com/2015/02/19/material-study-diamond-v2/
