Buckets render as if camera has moved a little

[Alex_M]

We're having a problem with some scenes when rendering with DR turned on. The buckets on some of the nodes render the image as if the camera has moved a little. This doesn't happen often but when it does, we have no choice but render on one machine otherwise the render is unusable.

Here is a quick render we just did. Notice how objects appear in different positions where the buckets went through:

[vlado]

Are you rendering from a camera or from a perspective viewport? Does the camera have a unique name?

Best regards,
Vlado

[Alex_M]

Yes, rendered from a camera with a unique name (there's just one camera in the scene).

[Svetlozar Draganov]

Would it be possible to double check that all machines participating in the DR use absolutely the same V-Ray build and the correct V-Ray Spawner is launched(in case you have multiple V-Ray/Max installations)?
Is there a chance to send us one of those problematic scenes(+assets) with explanation of your DR-setup so we could try to replicate the issue into our environment?

[Margarita.Stoeva]

Hello, Alex_M!
Such bucket offset may be related to lens file used in camera distortion parameters not being passed to the slaves (maybe they don't have access to the network location or the file is on the local machine and missing assets transfer for DR is turned off). This would be my guess. Did you have any success on locating the cause so far? I wonder what it turned out to be.

Best regards!
Margarita

[Alex_M]

Hello Margarita,

We didn't use camera distortion lens files. We still can't find what causes this problem and it still appears on some scenes. I will shortly send you the archived scene file at support@chaosgroup.com so you can see if you can find the problem.

Thanks for your help so far.

[Morbid Angel]

It happens sometimes, if for some reason on DR machine the scene is loading a slightly older camera position. I think in this case, you must restart spawner (but that didn't work for me) I never solved the issue

[Zdravko.Keremidchiev]

Please double check whether you are using identical V-Ray version on all of the machines in the pool.

[Alex_M]

All machines have the same Vray version - 3.20.03.

[vlado]

So it is a repeatable error with this scene? Or it happens with any scene?

Best regards,
Vlado

[Alex_M]

It happens every time with the provided scene. As far as how often it happens with other scenes, it's pretty rare, thankfully. I think we've encountered this 3-4 times only. The scenes on which this happens are diverse (not just exteriors). It has happened on interior project once if I remember correctly.

[vlado]

Ok then, perfect. If you haven't sent the scene to our support guys already, can you do that at support@chaosgroup.com so that we can find and fix the problem?

Best regards,
Vlado

[Alex_M]

The archived scene is already sent to support@chaosgroup.com . Let me know if the link has expired since I sent it via Wetransfer a couple of days ago.

Thanks again for your help.

[Dave_Wortley]

What is the scene system units for the scene, and how large is the scene?

[vlado]

What is the scene system units for the scene, and how large is the scene?

I don't think any of that matters; I don't think any of the previous suggestions matter at all either Will let you know more when we reproduce the problem here.

Best regards,
Vlado