Issue with motion blur when set to center on frame

[Hannes Drossel]

Hi!

We have found an issue with motion blur when having the shutter interval center set to 0. The setting 0 is a requirement for plate based VFX work as that would match the motion blur in the plate.

The issue seems to be that packed alembics without displacements are offset in time slightly.

The following image show the issue:

Top: Ball in houdini without displacement
Middle: Ball in packed alembic without displacement
Bottom: Ball in packed alembic with displacement

Attatching hip and abc file
motion_blur_issue.zip

This is pretty urgent for us as we get a mismatch in motion blur between objects. For example fur without displacement not sticking to the skin with displacement.

Cheers!
/Hannes

[Gosho.Genchev]

Hey Hannes,

Looking into this right away. Thanks for pinging us.

Best regards!

[Gosho.Genchev]

Heya Hannes,

I can't reproduce the problem here - I've tried with a build from Oct 1st, and the latest nightly build. It's possible the one you have has a problem, or maybe something was changed in the scene before uploading it.

Could you please check that the problem is still reproducible with the scene you've attached, and if so - ping me with the build date (from top menu -> V-Ray -> About V-Ray -> Copy to Clipboard)



Thank you!

[Hannes Drossel]

Hi Gosho.Genchev !


Thanks for looking into this so swiftly.

And you are right. With a later build this issue is fixed.

Thank you!

/Hannes