Refraction Artifact with Motion Blur

[situla]

Hi

I'm getting artifacts with refraction and motion blur when the object and camera are moving together through the scene(fig 1)
Everything is as I would expect without motion blur enabled(Fig2) and when only the object or camera are moving(Fig3) but when they move together they generate this artifact, I have tried everything I can think of geometry wise importing exporting, attaching to a box, motion blur samples, edit mesh, edit poly, reset xforms scene scale etc...this is a default sphere with a shell so mesh is clean, very simple glass shader.



Any ideas would be great as at the moment it seems I can't have the object and camera moving through the scene together with motion blur on.


Rendered in Max 2012/Vray 2.30.01

[Morbid Angel]

that indeed looks odd. Did you try motion blur from physical camera?

[situla]

yea both produce exactly the same results also tried various still and movie with differing shutter times and same in global motion blur no change

[vlado]

You can try increasing the "secondary rays bias" parameter a bit and see if it helps. If it doesn't, can you post the scene here?

Best regards,
Vlado

[situla]

Hi Vlado yea that was one of the first things I tried, after rebuilding the scene it seems to have been down to objects being a large distance from the scene origin.

cheers

[vlado]

Ah, ok.

Best regards,
Vlado