MASH motion blur issues

[Bart247]

Hi

I'm having issues with motion blur when exporting a MASH animation to an animated alembic or vrmesh files.
This happening on random frames.

Maya 2016.5
V-ray 3.52

Workflow
I'm animating a sphere falling over 120 frames with no change in topology, just translation and scale.
Creating a mash network (geometry, not instance) and using the time stagger to offset the animations.
Exporting a vrmesh file with animation and export vertex colors enabled.

Everything works except for the velocity values. When I export a velocity render element I can see the extreme values on the problematic frames.

The same issue occurs with an Alembic cache.

What can I do to bake the velocity values correctly.

[vlado]

That looks weird; is it possible to get us a scene where we can reproduce this to support@chaosgroup.com ?

Best regards,
Vlado

[Bart247]

Hi Vlado

I have attached the scene file

It's a simple MASH network in Maya 2016.5
You just need to export an alembic or vrmesh cache.



scene01_shot07_v03_FX_02_MASH.zip

[shaio]

Hi,
thanks for the scene. I'll take a look and will get back to you with some more information.

[shaio]

I was able to reproduce the issue with V-Ray 3.52. However I wasn't able to reproduce it with the latest 3.60 version of V-Ray. We've made quite a lot improvements since 3.52 so I would recommend if possible to upgrade to the latest version to avoid this issue.

[Bart247]

Thanks Ivan

We tried a similar mash technique on a new project and had no problems with V-Ray 3.60.

[yolov]

Thanks for letting us know, Bart247