Alembic cache with materials assignments

[Anonymous]

Hello everyone!

We are trying to establish a workflow between Maya and Blender. We are rigging an animation in Maya, caching an ABC, and bringing it into Blender. In that alembic cache, we are able to maintain UV sets but not shader information. Am I missing a check box somewhere?

Cheers,

MIGUEL

[mcw0]

Alembic will not carry shader info.  Only way to get that info is if the shader name is embedded into the mesh name.

[Anonymous]

Thank you for the answer
How could I embed it into the mesh?

[mcw0]

Include it in the name.  "mesh_chrome", "mesh_cloth", "mesh_glass", "mesh_shader1", etc.

[mjheberlein]

Shouldn't "Write Face Sets" at least store the shading group assignments per face set?

From Maya Help | Alembic Export Options | Autodesk:

Write Face Sets
Turn on to save per-face shading group assignments to the Alembic cache.
Maya only saves the shading group names to the file.
...

But I don't see any difference in file size or object properties with that export option enabled or disabled.

I'm looking into this because we would like to use Alembic caches exported from Maya and load them into Substance Painter. There, texture sets should automatically be created each time it finds a material.

When exporting Alembic caches from Blender, the file size is slightly bigger with "Face Sets" enabled. That makes it work as expected with Substance Painter.

Wich Alembic caches from Houdini it also detects all texture sets as long as the materials were assigned to face primitives in the scene.

Now I'm stuck finding the correct export settings to make it work with Maya.

@mcw0 Any ideas?

Thanks,

Michael

[mcw0]

I'm sorry that I haven't gone through this process myself.  But if the option works for Blender and Houdini, might this be a bug in Maya's alembic exporter?  Sorry I can't be of more help.

[mjheberlein]

Yes, that's possible. At least it is unclear what can be expected to happen when checking that box.

This KB article even states:

Note: To have the Alembic cached geometry inherit the shading network of the original geometry, turn on UV Write.

I'm not really sure what that's supposed to mean. It's probably not going to store the shading node networks in the Alembic cache but maybe a pointer to their names?

In any case, where would I best go to ask for more information or to report that possible bug?

[mcw0]

In the Maya Forums, under the Ideas forum, the last line mentions reporting bugs.

As for the UV write, it writes out the UV space so that textures are mapped correctly.