V-Ray 5 DR - Error/Warning: MtlUVWSelect requires....

[joel_mielisch]

Hi there

We're currently experiencing a weird error on all our render nodes while trying to use DR.

"Warning: MtlUVWSelect requires at least one UVW Gen instance and one String ID. Material XYZ .... uvwgen count: 0 string ID: 0


The error results in black buckets output when the nodes start rendering.
All scenes we're currently handling for a larger volume of assets were produced without errors before.

We're now working on revision of the projects and this error occured after moving the projects back to the
local drives of our workstations.

All materials are correctly linked and everything was placed in the correct path of origin.
Cinema R25 and V-Ray 5 and all Nodes are running the latest updates.


If someone has encountered this issue before, we'd really appreciate your input


Best Regards

[klex167]

I had the same problem with a medium size scene.
I found out that a large amount of clones and fur created those issues.
After recreating the scene again the errors disappeared and I'm not sure what exactly solved the problem. Are you using fog? I used the fog object in the scene as well.

Best - klex

[deyan.hadzhiev]

Hi joel_mielisch, this warning usually signals for invalid or unsupported material assignments on objects. Can you provide a simple scene reproducing the issue where we might take a closer look on what exactly may be causing the problem?

Best,
Deyan

[joel_mielisch]

Hmm thank you for your input.klex

No fog, no fur and not that many instances used in the scene... Probably 10-30 instances. But that's it.
We've split every product into it's seperate scene to keep each file size relatively small.

Around 300Mb per scene currently.

I'll troubleshoot further...

[joel_mielisch]

Hi Deyan, thanks for your feedback.

I'll look into it. I'll see if I can upload a cleaned file that replicates the error.

[joel_mielisch]

Edit: Problem still randomly occures. Even after deleting all unsupported Shaders and cleaning up the whole asset set.


It occures even more random now. First load up and first render works flawlessly - next one fails again.
Only thing that's a hint is that for some reason sometimes 1 random node states its "Starting Render Frame 2" instead
all others Rendering Frame 1. Frame selection is set to manual to double check...





-------------------------

Hmm it appears to be "solved" ...

There were indeed 4 materials from import that were faulty, but only in material manager.
They were not assigned to any objects in the scene.

After deleting and trying again - still the same error.
After closing and reloading the scene file the error appears to be resolved for now.

Thanks for your support