motion blur/ alembic

what is going on here. I have been successfully getting motion blur to work on alembic and all of a sudden I cant get it to work to save my life.
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STEP 1

STEP 2

STEP 3

STEP 4

STEP 5





Final no motion blur

APPROACH 2

I also tried a second approach which is to export the alembic, reimport to a clean scene, create into a vrayproxy from within maya and then reimport the proxy. this does not work either.

Approach 2: Step 1

Approach 2: Step 2. You can see the velocity was brought in just fine.

Approach 2: Step 3, whats odd here is the vrmesh, with the same frame range as the alembic does not match. it seems like first few frames are missing. this is an ongoing problem i’m experiencing and I am quadruple checking to make sure i have it set to 1-80 on alembic export, and proxy creation.

Approach 2: Step 4, you can see the animation is misaligned for some reason. as mentioned above.

Approach 2: Step 5





scene, alembic and vrmesh accessible here: Dropbox

very small file size

forgot to add this one, just to make sure:


I don’t think you export velocity at all. For alembic, adding “bifrostVelocity” to the “Motion Vector Color Set” should work even without velocities.

But did u see my image steps? I clearly am exporting the velocity. Am I missing a step? You can even see the velocity colors in the images I posted

Your vrmesh export is right. I did the same thing and it worked as expected. Which V-Ray version are you using? Maybe there is something wrong with the build.
About the alembic workflow, it seems Maya will not export the velocity, you must manually specify the Motion Vector Color Set:
https://knowledge.autodesk.com/support/maya/learn-explore/caas/CloudHelp/cloudhelp/2015/ENU/Maya/files/GUID-B5D406CF-922E-46BD-9238-9BB48347055D-htm.html

I will update our help to show this step.

I tried with 3.35 and 3.31

im confused, what are you saying is the problem? I still cannot figure this out. This is such a silly thing but i literally have spent 2 days doing this and cant get it to work consistently. it works when it wants to.