VRayUserColor and VRayUserScalar with Alembic attributes

[obeida_zakzak1]

Hello,

I would like to know if VRayUserColor and VRayUserScalar support Alembic geometry attributes when they are loaded via a VRayProxy in 3dsMax ? I could not make them work, so I am asking to know if I've missed something or if it's actually expected ? (3dsMax 2023 and VRay 6)

Currently I am exporting alembic cache from Houdini and I want to use some attributes for shading in 3dsMax.

I am already aware of the Vertex Color node in 3dsMax and it's use case for attributes/shading, but for workflow/pipeline reasons I want to get the attribute value based on it's name only, without having to know it's index in 3dsMax data channels/infos.

Side note : I have previously used VRayUserColor in VRay for Houdini, and compiled the shader as VRayScene, then assigned this shader inside 3dsMax on an Alembic cache with VRayProxy, and it worked perfectly. So I am wondering why it does not work when doing the same on 3dsMax side.

Thanks,
Obeida

[hermit.crab]

Currently, VRayUserColor/Scalar can be read from proxies (both .abc and .vrmesh) only in STD. We have an issue logged (internal bug-tracker id: VMAX-14331) about rendering it within 3ds Max. Otherwise, the native Vertex Color tex should be used.

[obeida_zakzak1]

Thank you for taking time to confirm this issue.

As for now I am exporting attributes from Houdini by naming them "Max_Map_Channel_##" so they get recognized by VRayProxy in the correct ID, so using the Vertex Color tex is more convenient now.