Unnaturally bright intersection of SSS

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

When using the “SSS ID” set in SSS [Fast SSS2, AlSutface] of V-Ray Next, the intersection becomes unnaturally bright.
Also, the sampling at the intersection is noisy.

Is there a solution?

Confirm with V-Ray Next Update 2 (The problem is from a long time ago)

sssProb.jpg
sssProb.jpg722×582 87.8 KB

sssprob.zip (113 KB)

2

Note that this does not occur in FastSSS2 Prepass mode.
However,V-Ray Next is not recommended to use this mode, so other solutions are needed.

prepass.jpg
prepass.jpg718×526 29.5 KB

3

anyone?

Is this a bug that has been abandoned?

4

I’m not sure how to solve this exactly. VRayFastSSS2 is a volume shader so it looks at what happens below the surface and if there are other surfaces there, they are taken into account. The configuration above is generally not physically plausible which leads to weird results not only in V-Ray, but also in other raytracers like Redshift, Corona, ART which all produce some kind of brightening. Arnold handles this slightly better, but it makes things darker instead of brighter.

I can try to solve this in some way, but I will need input from you to test the potential solution and let me know if it works well for you. If you email me to vlado@chaosgroup.com I will be able to get you a test build to try out.

Best regards,
Vlado

5

Thank you for the details. I understood the dilemma of the volume shader.

I will check if my customer wants a test build.

Best wishes,
-------
Yuji Yamauchi
OakCorp Support