diamond

[fario]

hello,

How can I get a better result in diamonds? please.

Thank you.

Antoine

[Ed]

Antoine, you may want to see this discussion:

https://www.keyshot.com/forum/index.php/topic,10396.0.html

My recommendations are:

1) In Settings, set Ray Bounces to a higher number.  I use 50.

2) Use an HDR containing multiple smaller light sources. Indoor office or indoor store HDRs work well.

3) Use an HDR that has high contrast areas.  Low-contrast, blurred or cloudy HDRs may not give optimum results.

4) Avoid pure black & white HDRs.  A small amount of color is needed if you want lots of dispersion.

5) There is interaction between the HDR and the gem material ABBE number.  Experiment to find the sweet spot between them. A very small change in HDR rotation or height can make a big difference.

6) Make sure the stone does not intersect with any other geometry.  The stone should "float" by a small amount in the setting.

7) The HDR that gives the best result for the diamond may not be the best for the other objects in the scene.  Use a Clown Pass and render the diamond with one HDR, and the other objects with another HDR.  Combine the result in Photoshop.

I made a test render using two different HDRs: 

The top image has more dispersion than I would use, but it shows what is possible.

The bottom image shows an HDR that has no color and is more blurred.

Ed Ferguson

[fario]

Ed thank you for your explanations!
All this will be very helpful for me.
I'll test.

Antoine