Vray Proxy Fatal Error

[shegmann]

I have encountered a problem when making Vray Proxies in Maya 2019.3.1. Maya appears to create the proxy successfully. However, it crashes (Fatal Error) as soon as you attempt to interact with the Shading Group associated with the vrmeshmtl (either through Hypershade or through the Attribute editor). This crash only occurs when the shading network has an external connection (such as a colorCorrect or file texture node) feeding into it after clicking on the Shading Group node of the Vray Proxy in the Hypershade.

1. Here is the model I wish to make a Vray Proxy of with its corresponding Shading Network.

It is shaded with a simple Vray Mtl with a file texture node connected into the Factor component of a Color Composite node.

1. Here is the same model made into a Vray Proxy with the same Shading Network and corresponding proxy_vrmeshmtl and proxy_vrmeshmtlSG node.
2. However, when I interact with the proxymesh_vrmeshmtlSG (shading group) node, Maya crashes.
3. Oddly enough, I am able to create a successful Vray Proxy when I have a single VrayMtl with no other nodes feeding into the model (such as a file texture, color composite, etc.)

5. This is a repeatable error, occurring on multiple machines. This also occurs when opening up previously created VRay Proxy scenes. The other nodes of the Shading Network respond normally and do not cause any crashes or abnormal behavior. I am also able to graph the network from the swatches. However, any interaction with the Vray ProxySG immediately causes a Fatal Error crash.

6. I have tested older files from a few months prior which were made into Vray Proxies, and they do not have the same error. Also, the VRay Proxy scenes that will crash in Maya 2019.3.1 are stable when opened in the latest Maya 2020 release. We didn’t have plans to change which version of Maya we are currently using until a few larger projects are completed, but this stability issue with VRay Proxies is rather worrisome.

Thank you in advance for your help!

[hermit.crab]

Thanks for the report. I am able to reproduce the issue on a simple scene by simply plugging in a texture to the VRayMtl plugged in the Shaders of the VRayMeshMtl and afterward opening its shading groups. I've logged the issue (internal bug-tracker id: VMAYA-9759) for developer analysis. A workaround might be to apply materials directly to the proxy itself (bypassing the meshmtl medium); if multiple materials are present in the proxy, however, you would have to export objects separately on a material basis.

[shegmann]

Thank you, Aleksandar. We appreciate the work arounds offered, but neither is particularly feasible with our workflow right now. Hopefully this is something that can be addressed soon! We'll keep an eye on things. Many thanks, Sarah.

[hermit.crab]

Just to keep you in touch. the issue seems to be a Maya related bug, which is already forwarded to Autodesk for investigation.

[francomanko]

would this be a similar issue Im getting where im 'duplicating special' a proxy and it crashed maya..repeatedly?

[shegmann]

Hey francomanko - our workflow has us primarily creating instances of groups of proxies. We can do that without issue even with the current Shading Group crash problem. Not sure what settings you are using under Duplicate Special, but instancing doesn't seem to be affected.

[hermit.crab]

francomanko It may be. Could you send an example scene to support@chaosgroup.com where the crash is present?