Light Exclusions Broken With SSS

V-Ray V-Ray for 3ds Max Issues
1

When you have SSS enabled in a VRayMaterial if you exclude the object from a light the light still affects the SSS! That’s not good…

Max 2023 VRay Build 32397

Any chance of a quick fix? Thanks.

2

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Sphere on the left is excluded from the light above it, yet it still get SSS from it. The right is not excluded from either light.

Scene attached.
SSS_Light_ExclusionBug.zip (53.2 KB)

3

It’s a known issue (internal bug-tracker id: VMAX-12526). You can workaround it by either switching the SSS’s Illumination mode to Uniform or removing the excess info in post through a VRaySSS2 RE and a mask.

4

Thanks, Aleksandar. Is there a mathematically accurate way to remove it for just a single light using a Light Select, VRaySSS2 pass, and a mask pass?

5

You could create a VRayLightSelect for SSS2 only for a particular object or shader through LPE.
1. For a particular object - add an LPE label in the V-Ray properties; add an LPE with the following code:
C<TD'obj1'>(.+L|.*[OB])
2. For a particular shader (label is m + shader name):
C<TD'mCherry'>(.+L|.*[OB])

6

LPE, of course! Thanks for this.