vray proxy bug?

[Ekenryd]

Hello,

We recieved some cad car models and when turning them into vray proxies, everything worked fine except for the cars registration plates. If I turn both the back and the front plate into a combined proxy, the front plate can't display its shader correctly (it seems to be something with the uv). If I turn them into seperate proxies, everything works as expected. We've tried every trick in the book to get them working, merging verts, recreating uvs, export as obj and import, etc but it still does not work when the two meshes are combined into one proxy.

Any idea what the problem is?

I've attached a scene with three groups: the original geo, a combined proxy and seperate proxies. If you render the combined one you'll noticed that the front plate gets pure pink.

[Morbid Angel]

One of them probably has reversed normals.

[Ekenryd]

Like I said, we've tried most standard things, including checking normals, but good with more suggestions. Our main brain here thought it might be a vray proxy bug, that's why I put the scene here.

[t.petrov]

Any idea what the problem is?

It seems that the cause for the problem is that the two objects have uv sets named differently.
The result of the export is a proxy with two uv sets, but not all faces have uvs in both sets.
I've modified the uv sets names on both objects and the exported proxy rendered fine.

You can debug such issues using the "ply2vrmesh -info path/to/file" command.
See an example for your file:

$ ply2vrmesh -info /tmp/vrayProxyBug/regplatesBoth.vrmesh 
Converter of .ply .obj .bin .geo and .abc files to .vrmesh files
Copyright (C) 2003-2013 by Chaos Group Ltd. All rights reserved.
Build from Oct  3 2013

Information for "/tmp/vrayProxyBug/regplatesBoth.vrmesh"
  Number of frames: 1
  Number of voxels: 3
  Reading voxels... done                            
  Total number of triangles: 2,064
  Preview triangles: 500
  Channels:
    Vertices
    Faces
    Vertex normals
    Normals faces
    Face info
    Maya info channel (data is valid)
    Number of texture channels: 2
    Texture channels list: 0 - 'dressing:uvw:0_428', 1 - 'dressing:uvw:0_429'
  Bounding box: [-93.990, 28.337, -26.000] - [358.621, 42.642, 26.000]
    UV sets: 2 ('dressing:uvw:0_428', 'dressing:uvw:0_429')
    Color sets: 0
    Shader sets: 2 ('regBackVM', 'regFrontVM')

Probably it is a good idea to run a script that unifies the names of the uvsets for all meshes that have single uvset.

[svetlozar.draganov]

It works fine if you combine both meshes before Proxy-export (Mesh>Combine).
Please view the attached file ( you have to restore proxy path ) 498_Proxy_Issue.zip