Motion blur problem for VRayProxy of animated mesh

[Vipera]

I have created wind animation for the tree models. Animation for each tree has 200 frames loop sequence. I have exported animated mesh of each tree to VRayProxy. The problem with motion blur happens on frame 200, where it has end of loop sequence. It looks like VRayProxy fast rewinds animation from frame 200 to frame 0 and that causing motion blur artefact. How can I deal with such problem?

[vladimir_krastev]

Hi, thanks for posting. You can't have motion blur in the last frame of your animated movement. This is true for non proxy geometry as well. If you export 199 frames of your 200 animated frames there should be no issues.

[Vipera]

I will try export VRayProxy 199 frames instead of 200. Thank you for suggestion. By some reason mesh animation exported to Alembic (.abc) file doesn't have such problem. If frame 200 mesh is exactly the same mesh as frame 0 then there shouldn't be motion blur anomaly. I suspect something is wrong in how VRay calculates motion blur in VRayProxy loop animation between first and last frame of sequence.

[vladimir_krastev]

Hi, could you archive and send us your test scene for review? Please do that here or trough the support contact form.

[Vipera]

Here is the link to archive with Max2024 file with plant animation loop (0 - 200 frames) in VRayProxy and Alembic formats. The problem with motion blur happens on frame 200, where loop sequence ends.
Dropbox link

[vladimir_krastev]

Hi, I reviewed your scene. Are you sure you are exporting the proxy correctly?
You have to do it like this:

[Vipera]

Yes, I export proxy like this. How else can I export animation or make it incorrectly? I made test and exported animation 0-199 frames instead of 0-200 frames as it was suggested. And proxy version 0-199 frames does not have issues with motion blur. I used tyLooper modifier 0-200 frames to make loop for animated trees, if this makes any effect how proxy created.

[vladimir_krastev]

Hi, thanks for getting back to the tread.

I used tyLooper modifier 0-200 frames to make loop for animated trees, if this makes any effect how proxy created.

This could be a part of the issue. From your scene the proxy does not have motion blur in any of the frames and the in frame 200 it explodes.

Here is how the proxy and alembic look for frames 0-199:

This is how the proxy and alembic look for frame 200:


I can not reproduce this in a simple scene. It looks like an issue with this specific proxy.
If you archive and send us the original scene and steps that you do for the proxy export we could investigate it further.

[Vipera]

This is not a specific proxy. This issue happens to all trees I exported. I could provide the original tree mesh before export to VRayProxy but it involves two plugins - GrowFX 2.0.1 and tyFlow 1.106. Please confirm that you have such plugins for the test.

[vladimir_krastev]

Hi, we have the plugins. If we do not have a certain plugin that a client uses we buy them so we are able to help. Try to simplify the setup as much as possible and leave only the necessary for the issue to reproduce. This will speed up our answer.
To recap - you export this GrowFX and tyFlow generated mesh to alembic and it works. After this you export exactly the same object to a VRayProxy and it does not?
Please send us the files to our support contact form and add a link to this thread in the description.

[Vipera]

Yes, this is correct. Here is the file attached, which has two tree models. One model is GrowFX tree model with wind animation. Another tree is lowpoly tree mesh with added Noise modifier to simulate the wind. There is tyLooper modifier on top of each tree mesh, which creates loop for animated mesh in a range 0-200 frames in my file. Export both tree meshes to VRayProxy with animation range 0-200. Set both exported VRayProxy to play as a loop animation. Render exported VRayProxies on frame 200. Both trees have the issue in camera motion blur. This motion blur artefact doesn't happen when I export proxies in animation range 0-199 frames or to Alembic format.

[Vipera]

Just checking if someone was able to dig this problem yet.