(Resolved) Motion Blur x Light Material bug/issue - URGENT

[ajvisuals]

Hey all,

Having an issue where when I turn on motion blur, something funky happens to my material that uses a BRDF light node (see images attached)

Without motion blur, you can see the light uniformly fills the edges of the glass material. Turn MB on, and it glitches out as shown in the second image.

The project has a deadline on Friday so would love to get this fixed ASAP.

[chakarov]

Hi ajvisuals , try to increase "Geometry Samples" in MotionBlur settings in V-Ray ROP, maybe 3 or 4.

[ajvisuals]

Hey chakarov I've tried upping the geo samples and it has no effect. I have been debugging today and found that it has something to do with the animated geometry.

Here's a simplified version of the scene. If you switch between animated geo and frozen geo the problem disappears.

https://we.tl/t-HbpHcRommg

Not sure what could be causing it?

[chakarov]

Hi ajvisuals , in order to use motion blur for objects with changing topology, like flip sims, you should change to "Velocity Blur" in geo node properties "Render" > "Sampling" > "Geometry Velocity Blur".

[ajvisuals]

chakarov thank you so much for finding the problem. Apologise for any time wasted. I wasn't aware of this so a lesson learned. Massive thank you!