Page 1 of 1

Universal Specular produces different result in 2020.2+

Posted: Mon Aug 30, 2021 10:25 pm
by kabakZ
Hi, I don't know if it's a bug or some kind of change in the engine, but Universal Material with Specular type looks different in 2020.2 and up compared to 2020.1.5

2020.1.5 Universal, Specular
Spec-Octane x22.jpg
2020.2.X Universal, Specular
Spec-Octane x23.jpg
2020.1.5 Universal, Specular-GGX
Spec-GGX x22.jpg
2020.2.X Universal, Specular-GGX
Spec-GGX x23.jpg
However, Universal Material with type Diffuse and Specular Material look identical. The strange behavior applies only to Universal Material with Specular type. RTX ON/OFF does not affect the result. Nested Dielectrics are OFF.

2020.1.5 Universal, Diffuse + medium
Diff-Octane-med x22.jpg
2020.2.X Universal, Diffuse + medium
Diff-Octane-med x23.jpg

Re: Universal Specular produces different result in 2020.2+

Posted: Thu Sep 02, 2021 2:23 am
by wallace
Hi,

This was indeed a fix for the universal material when you mix the diffuse reflection lobe with the specular transmission lobe. The problem before was that the diffuse reflection was lobe was causing some darkening when the ray exits the material from inside (2020.1).

Cheers,
Wallace

Re: Universal Specular produces different result in 2020.2+

Posted: Sun Sep 12, 2021 10:12 pm
by kabakZ
Thanks for the clarification. Is there any chance to undo the fix or add a legacy mode? Because this fix completely killed the skin shading and works the opposite way with Medium Scattering node with negative phase. Now it began to look way darker in 2020.2, when it worked just fine in 2020.1

Re: Universal Specular produces different result in 2020.2+

Posted: Mon Sep 13, 2021 10:52 am
by linograndiotoy
Could you please share a simple scene showing the issue and also images showing how it was looking in previous versions? Thanks!