vMaterials not being exported correctly with USD scene from Create

I have been working on a scene at the agency where I work, and I decided to show them the potential of Omniverse Create. I succesfully exported my scene as USD from C4D, and since there is no way to directly export Octane materials without baking, for simplicity I then used the vMaterials within Omniverse.

The problem
Whenever I reopen the scene, the materials are persistent. But if I import the USD file into Blender, none of the vMaterials displays correctly, except the few ones that I created myself. Materials names and assignments are there, but their node trees are empty. If then I export this same USD from Blender and open it in Create, all materials are blank, again except the few ones that I created.

Am I missing something when assigning vMaterials? Is there a way to make sure the get exported properly so that Blender can read them correctly?

Thanks a lot for any help.

Hello @robin.bervini! I’ve shared your post with the dev team for further assistance. It may help if you could share your USD file with us. You can attach it here or email it to me at: omniversecommunity@nvidia-omniverse.atlassian.net

Hi @robin.bervini. We currently convert only OmniPBR and OmniGlass MDL materials in Blender. (This is done through the Universal Material Mapper (UMM) addon.)

OmniPBR and OmniGlass materials authored in Create should import into Blender and can round-trip losslessly from Blender to USD.

There is documentation describing the Blender material templates that are used to represent these MDL materials:

https://docs.omniverse.nvidia.com/con_connect/con_connect/blender/material-templates.html

Also, note that the UMM addon is currently being revised to allow converting a wider range of materials in the future. Please let me know if you have any questions.

1 Like

Thank you Wendy. Unfortunately, I cannot share such file because of confidentiality with our client. But for troubleshooting I will try on a test project and share if I don’t solve the problem after following @makowalski 's instructions.

I do have UMM addon enabled, so I was very surprised that the materials used in Create (note: all picked from the Materials tab > Base; vMaterials) did not export/import correctly. Are they not MDL then?

Thank you both

Hi @robin.bervini. In Create, please be sure to assign OmniPBR or OmniGlass and these should import into Blender. (Not all MDLs are supported, just these two.) I just tried it to confirm that it works (Blender 3.4.0-usd.102.0 from the Omniverse launcher). Please let me know if this doesn’t work for you. Thanks.

Hello @makowalski and thank you for taking the time to reply.
So if I understand correctly, not all materials from the vMaterials 2 collections are either OmniPBR or OmniGlass. Is that correct? For instance the material Brushed Iron (see image attached) does not get transfered over. I guess I thought that all vMaterials where compatible but it is true that Blender is not mentioned on the vMaterial asset page.

You are correct, not all materials in that collection are OmniPBR or OmniGlass. One way to add OmniPBR or OmniGlass materials for testing is through the Create -> Material menu:

1 Like

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.