Square Artifacts in Adaptive Lighting with VRayHairNextMtl

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

Hey guys!

We’ve come across an issue that seems related to something you’ve already noted in your patch notes:

PatchNote for build 6.20.02 Square Artifacts with adaptive lights after updating to 6.20.00 in specific scenes

We’re seeing similar square artifacts in 3ds Max 2024 with V-Ray 6.20.06, specifically when using adaptive lighting.
I’ve attached a really simple scene with the bug

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Steps to Reproduce:

  • A close-up shot of an object (e.g. a teapot).
  • Another object in the scene (but outside the camera view) with a VRayHairNextMtl assigned, or a VRayMtl referencing a VRayHairNextMtl (tried with a shader imported from Houdini).

Observations:

  • Zooming out with the camera removes the artefacts at a certain point
  • Adding camera clipping doesn’t help.
  • Switching to FullLightEvaluation also removes them.
  • Moving the problematic object further away from the camera target eliminates the issue.
  • This behavior does not occur in 3dsmax 2023 with V-Ray 6.10.09 Build 32197
  • We tested other materials, and only VRayHairNextMtl seems to trigger the issue.
  • Appear in IPR aswell as Bucket rendering
  • The more you have lights, the more you see the bug (but managed to reproduce it with a VraySun).

​I’ve checked the releases notes for the latests nightly builds past 6.20.06 Build 0000 but didn’t see anything related to this specific case.

We’re a bit stuck, as asset production is nearly complete using this version. We’d prefer not to upgrade to V-Ray 7 for this project, and rolling back to 6.10 isn’t ideal either.

Let us know if there’s any known workaround or if it is possible to get a nightly version of this build, thanks!

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TATToChaos_Vray6206.zip (189 KB)

2

The issue seems to be fixed in the latest V-Ray 6 stable builds. Note, however, that you’ll need to adjust your lighting/exposure control.

3

Checking the latest build right now, can you elaborate on “adjust lighting/exposure control”?

4

I just noticed that the lighting looks different with the stable build, as if the Exposure Control result was different.

5

Looks allright in the stable build, for the exposure control I feel like it’s on my side I must have saved the scene with different lighting compared to my screenshot while testing