Support float2 (vector2) uv channels

[Dubbie99]

If you export a second set of UVs from maya as an ABC, they come into as a vector2.

Unfortunately VRay ignores this (I guess it is looking for a vector3?) It would be great if I didn't have to unpack and promote the vector2 UV to vector3 UVW for VRay to work with packed alembics with more than one UV channel.

My use case is an object with UDIMs for the main UVs and then a second set of UVs that has everything on one UV sheet for comp to use as a UV pass.

[bdancer]

Could you pls send me such an abc file?

[Dubbie99]

Thanks Andrei,
I have sent a sample file to your email.

[daeschri]

Houdini in general is expecting uvs to be 3 float vector, and this is an Autodesk issue that has been logged and long outstanding. If you were to take the same model from maya with multiple uv sets and export a FBX instead you'll see that maya exports the additional uv sets at 3 float vector not 2 like it does with abc.
Or at least did the last time we checked. Haven't tested with Maya 2022.

But it's an inconsistency in the way Maya exports the uv sets and they should fix it.

Our solution is to convert the 2 float vector uv set to 3 float vector on export in maya. So when it comes into houdini its already setup correctly and you don't have to unpack it.. But it's all to compensate for Autodesk issue.

If vray can support it, I wouldn't complain but I think Autodesk needs to get there stuff in order.

[bdancer]

V-Ray supports such channels from .abc.