VRayMesh not rendering mesh visibilities correctly after scene re-open

[colorbleed]

Issue

We're having problems where when opening a scene and starting a render the VRayMesh does not obey the visibilities set in the Mesh visibility lists. Whenever one clicks the VRayMesh and the node has been active in the Attribute Editor and has shown the Mesh Visibility list of the node the problem resolves itself.

In the same way the viewport doesn't show the correct meshes when re-opening the scene. That only updates after a visibility is manually toggled again by the artist.

Tested on

V-Ray for Maya version 3.45.01, revision 26849 from Jul 6 2016, 03:28:12 (Nightly build)
V-Ray core version is 3.25.01
Maya 2016 Ext. 1 SP6
Windows 7

Extra information

We're loading Alembics (.abc) in the VRayMesh, not a .vrmesh.
We have "Use full names" enabled on the node. (Without this some of our other tools/scripts didn't function well; also disabling this loses the mesh visibility settings)
We have "Instancing" disabled on the node. (With this enabled similar objects were messing up when assigned different shaders, so we disabled this for most vraymeshes)

To reproduce

1. Import Alembic as VRayProxy
2. Enable "Use full names" and "Instancing" (not sure if required, but this is our setup)
3. Toggle some visibilities
4. Save scene (we use .ma format)
5. New file, then open scene
6. Render

At this stage the render is not obeying the state as were set on the node. Similarly the Viewport is not an accurate representation.
Whenever you "click the mesh" and have the VRayMesh node active in the Attribute Editor showing the Mesh Visibility list and render after that it seems to "fix" and render correctly.
Viewport remains messed up nonetheless.

[vlado]

Thanks for the report, let me see if we can reproduce it here.

Best regards,
Vlado

[tashko.zashev]

The mesh visibility seems to be broken between 21/22.03.2016 nightly builds and we are working on the fix right now.

Will keep you posted.Thanks!

[colorbleed]

Thanks for the heads up!

We're using the recent nightlies because of another fix we needed, so would be great to get another nightly out soon where this one is also smashed!

[Mihail.Djurev]

This should be fixed in the latest nightly build and will be included in the 3.40.03 release.

[colorbleed]

Hey Mihail,

I'm not seeing this mentioned in the nightlies release notes.
We tried a newer nightly version yesterday and the problem still seemed to exist (doing only some preliminary testing at the time).
Are you sure this is available already?

[Mihail.Djurev]

Sorry, I might have misled you.
The fix should be available in the nightlies build 26857 and later. It will also be included in tomorrow's stable 3.4 nightlies. However, it is not included in the stable 3.4 nightlies from the 14th (build 26859).

[colorbleed]

We tried 26860 and the problem described above to reproduce does seem to be resolved.

Nevertheless visibility overriding on referenced VRayMeshes doesn't seem to work, whereas before it was actually stored within the scene. Now it just seems to be "ignored" completely. Is that correct?

To reproduce

1. Import Alembic as VRayProxy
2. Enable "Use full names" and "Instancing" (not sure if required, but this is our setup)
3. Toggle some visibilities.
4. Save scene as A.ma
5. New file, then reference A.ma
6. Render (works fine! Has toggled visibilities from A.)
7. Toggle some visibilities (overrides in this scene)
8. Save scene as B.ma
9. New scene, re-open B.ma
10. Render (wrong visibilities; overrides on the reference done in B.ma are missing)

In this case it seems the list itself is also wrong.

Aside from visibility we've also been getting "shader assignment" issues where it seemed shaders got mapped incorrectly. Though I haven't been able to accurately reproduce it and debug where it's coming from.

[yolov]

"Use full names" actually breaks the visibility lists, but that's a separate bug. It's already logged to our bug-tracker and we'll let you know when we have a fix for it.

[colorbleed]

Thanks for pointing that out. Looking forward to that fix and hope it resolves the issues we're having.

[colorbleed]

Was able to do some more debugging regarding the latest problems we had with VRayMeshes shaders getting mapped incorrectly. It seems whenever the shaders connected to a VRayMeshMaterial are referenced and the scene is reopened the VRayMeshMaterial doesn't render correctly.

For example:
- Create VRayMeshMaterial
- Reference shaders -> connect to slots on the material (our pipeline manages this), but it's a straightforward connectAttr.
- Renders correctly.
- Save scene
- Reopen scene.
- Renders wrong.

The reference edits do seem to be stored, as such it "looks like it should work" yet upon reopening the scene the connections result in a different render.
Hadn't gotten around to investigating further than that, but I hope it helps tracking down this particular problem.

We're tackling some bigger scenes at the moment for a project and would be great if there's a way to get this smoothly sailing.

[yolov]

Thanks for the pointer. This is logged to our bug tracker, so the thread here will be updated once we have a fix.