VrayMultiSubTex + Motion Blur = Huge slowdown

[gmlealll]

Rendered in 3dsmax 2020, Vray 6.00.21,
Windows 10,
AMD Ryzen 9 5950X 16-Core Processor 3.40 GHz, 128GB

Found another issue with VrayMultiSubTex , if you have a VrayMultiSubTex in the translucency slot and Motion Blur enabled, the scene becomes impossible to render.

Look at the image attached with just a couple of trees. With just a bitmap in the translucency slot it takes 43.9 seconds to render but with a VrayMultiSubTex takes it takes 29 minutes. this was rendered at 480x270

If you disable motion blur it renders in 38seconds

[^Lele^]

We'd need to see the scene, if at all possible.
Please submit a ticket (f.e. via the V-Ray menu in max) and point to this thread.

[gmlealll]

Lele,

I just uploaded a sample file.

Found something else before summiting the file. If you collapse the animated proxy to an editable mesh, it renders fast, even with the VrayMultiSubTex in the translucency slot

[^Lele^]

Thank you!
Would you have the ticket number?

[gmlealll]

yes

#85441

[^Lele^]

Thanks a lot!
The issue is confirmed, our internal ticket unmber is VMAX-13023.

[gmlealll]

Thanks Lele

[^Lele^]

This is reported as fixed in the latest stable for 6.1.