V-Ray Proxy and Attributes

[david.anastacio]

Hi,

In the V-ray Proxy page of the V-Ray manual it reads: "Meshes are exported to a special .vrmesh file format. This file contains all geometric information for a mesh such as vertices and face topology as well as texture channels, face material IDs, smoothing groups, and normals. In short, everything that is needed to render the mesh is included in the file."
But if the mesh contains extra attributes those are not being included in the file, is this a bug or a feature? Only UVs, normals and matIDs are saved?

Best,
David.

[glacierise]

Does the force attributes list add them in?

[david.anastacio]

Does the force attributes list add them in?

In the V-Ray Proxy Expoert SOP node there is not option to force attributes, are you thinking of the V-Ray scene export maybe?

Best,
David.

[glacierise]

Yeah. How would vrmesh be better than alembic?

[david.anastacio]

Yeah. How would vrmesh be better than alembic?

Seems quite faster to start rendering than with alembics files, at least in some geos that I tested.

[glacierise]

Ok, that's interesting, thanks - if you end up with some numbers that would be very cool read, can test on our end too

[david.anastacio]

The test I did was with with 20000 scattered point with small rocks. The resulting Alembic was like 700mb and the vray proxy around 200mb. The render start hanged for a couple of minutes when it started loading the alembic, but with the vray proxy started and never hanged.
From what Gosho told me today, this is not really the expected behavior, the difference from alembic to vray proxy should be minimal, so this could have just been an exception.

Best,
David.

[glacierise]

Aha, you put in the result of the scatter in the alembic? Using the instances option? We've seen wide variety of results there, based on how many objects we instance, it's really good with small amount of highres instances, and bad with big amount of lowres instances

[gagui]

Hi, how can I extract attributes from a imported .vrmesh proxy?
Thanks!

[Gosho.Genchev]

Hey gagui ,

For export out of Houdini, we generally recommend artists to use the Alembic format - it's well supported natively in Houdini, and we've improved V-Ray's ability to handle advanced Alembic workflows to be up to par.
If you're bringing a .vrmesh exported from another software package (e.g. Maya), you can use the UserColor / UserFloat VOPs to sample their attributes.

Best regards!