Alembic as Proxy, shaders assignments?

[brobins]

Hi there

What is the general workflow for using alembic files as vray proxies and having control over the shaders via the VrayMeshMtl?

If I export a .vrmesh and load as a proxy I usually get a list of all the shaders assigned at the time, these can then be overridden via the VrayMeshMtl. Using the same workflow but exporting an .abc file I only get a list of shape names in the VrayMeshMtl rather than the shaders. To my knowledge Maya writes the shading group names to the Alembic file by default, can the VRay proxy read this information rather than listing the shape names?

I am probably missing something obvious here. Would appreciate any pointers.

Thanks in advance.

Ben

[vlado]

To my knowledge Maya writes the shading group names to the Alembic file by default, can the VRay proxy read this information rather than listing the shape names?

We have to check if Maya writes this information; in any case we don't do anything about it - you will have to reassign the shaders manually. Of course, if this can be automated, it would be best, but I'm not quite sure what would be the best way to do it. We could add a button that reads the materials and attempts to find them in the Maya scene and automatically assigns them to the mesh material?

Best regards,
Vlado

[brobins]

It would make most sense (to me) to keep a consistent workflow between .vrmesh and .abc

Its great that a vray proxy can read either file format but its quite confusing having 2 different workflows, for controlling shader assignments specifically. If shading group information is written out with the .abc by default it would be most useful to read this in as you do with a .vrmesh file and populate the vrmeshMtl list with shader names rather than object names.

Many Thanks,

[vlado]

Ok, will look into it.

Best regards,
Vlado

[Morbid Angel]

brobins, so when you export abc from maya, how do you import it back with materials or assignments? (if you don't use vray proxy)

[brobins]

brobins, so when you export abc from maya, how do you import it back with materials or assignments? (if you don't use vray proxy)

I dont generally use alembic for rendering for the reasons mention above. I generally use .vrmesh for rendering and alembic for GPU Cache to give a better, faster viewport representation of the model. This requires me to export the model twice which isnt optimal, especially on projects with a large volume of assets.

[ivaylo.ivanov]

Yep, we are trying to fix the proxy viewport performance for 3.3, so you don't need to use gpuCache for this. Alembic seems to have a similar issue though - it has 2 exports - standard and for a gpu cache. They produce different results. AFAIK, the gpu cache one has some basic materials exported. XGen has yet another alembic export, which fully supports materials, but by using additional files - one to match objects with shaders, and another one to hold the shading network. VRay supports this, but Maya's standard exporter can't produce the extra files. So if the proxy preview is your major issue, it seems the easiest issue to fix.

[brobins]

Yeah, that's my only issue with it really. If you can fix the proxy to display similar to a GPU Cache with the same speed advantages then you're onto a winner.