Material connection get lost

[Micha]

Hi,

I have a scene where all object lost the material type "V-Ray Material" and got "Custom". If try to assign the V-Ray materials again or set the type "V-Ray Material" than a copy is created with #1 added to the name. I don't know what caused this issue.

But I found a way to fix it, maybe someone need it too:

* open the Asset editor
* start _SelMaterialName
* select a material per "Select material name" tool list but don't press ok -> the objects are selected
* assign the material per V-Ray Asset editor and the material is clean assigned without a copy

-Micha

[Micha]

Edit: I thought I lost all material connections again, but it was a few only. I will try to find a repeatable scene.

[konstantin_chaos]

Here's a summery of all the cases we found that cause some kind of material duplication and our recommendations in each one:

Case 1 (reset to defaults):

1. Create a V-Ray material
2. Right click on it in Rhino's material list
3. Select Reset to Defaults
4. The connection between the V-Ray material and the Rhino one will be lost (a self-duplicating material is produced)

This issue is fixed with the last update - V-Ray 5 for Rhino, update 2.1
* Upgrading V-Ray will not fix any scenes already saved with the buggy material.

Case 2 (altering V-Ray materials without V-Ray being loaded as a plugin):

1. Create a V-Ray material in any scene
2. Apply it to an object
3. Save the .3dm file
4. Disable V-Ray from Rhino's plugin manager
5. Restart Rhino
6. Open the .3dm
7. Change the type of the V-ray Material from Placeholder to Custom
8. Save the .3dm
9. Re-enable V-Ray
10. Open the last version of the file
11. The connection between the V-Ray material and the Rhino one will be lost (a self-duplicating material is produced)

We still don't have a good solution for this.
The correct thing seems to be - deleting any V-Ray materials that don't have Rhino counterparts on scene load.
This will, however, permanently delete the V-Ray material from the project and if the buggy material was not produced by the 'intentional' steps described in Case 2 this can be a problem.
* If we find a good way to address all other cases then the solution for Case 2 would become - deleting the V-Ray material.

Case 3 (saving a file containing V-Ray materials while V-Ray is not loaded as a plugin):

1. Create a V-Ray material in any scene
2. Apply it to an object
3. Save the .3dm file
4. Disable V-Ray from Rhino's plugin manager
5. Restart Rhino
6. Open the .3dm
7. Save the .3dm
8. Re-enable V-Ray
9. Open the last version of the file
10. The V-Ray material is no longer applied to the scene object. There is a copy of the material with the exact same name and type set to Custom (this one is applied to the object).

This case does not produce self-duplicating materials but is still an issue.
The only thing we can do about this case is report it to McNeel.
V-Ray is in no way involved in the issue. We tested with other 3rd party plugins and the same exact behavior is observed.

!! Case 4 (opening a 3dm file by double-clicking right after V-Ray is installed):

1. Install a V-Ray version different than the one you have
2. Double-click on a 3dm file containing V-Ray materials to open it
3. Rhino starts and then starts loading V-Ray for the first time
4. Unfortunately the scene gets loaded before V-Ray is initialized which leads to issues
5. Some or all of the scene material will become 'self-duplicating' ones
6. At this point the best course of action is to re-open the project...

This is another thing that we'll discuss with McNeel.
It is however very easy for you to avoid:
After installing new V-Ray version start Rhino in the regular way at least once.
Wait for the V-Ray plugin to be initialized before opening a file.
We will continue looking into ways for improving the UX in this case but it's not entirely up to us.

If anyone finds another way to produce self-duplicating material, please let us know!

Regards,
Konstantin

[Micha]

Hi Konstantin,

thank you for the detailed info. I can' say for sure which of the reason caused the trouble. Maybe it was caused during an update. I'm parallel using VfR 4 and 5 and I need to temporary disable the plugin to get both running. Maybe I have started the scene during the plugin was disabled. But I thought the update was a day or so before.

Would it help if you get the file or can't be seen what caused the disconnection?

Best regards,
Micha

[konstantin_chaos]

Hi guys,

Hi,

I have a scene where all object lost the material type "V-Ray Material" and got "Custom". If try to assign the V-Ray materials again or set the type "V-Ray Material" than a copy is created with #1 added to the name. I don't know what caused this issue.

But I found a way to fix it, maybe someone need it too:

* open the Asset editor
* start _SelMaterialName
* select a material per "Select material name" tool list but don't press ok -> the objects are selected
* assign the material per V-Ray Asset editor and the material is clean assigned without a copy

-Micha

First of all I want to thank Micha for looking into this and suggesting a workaround.
Unfortunately I have to point out that the workaround described in his post is not a complete solution for the problem.
The materials will actually continue to get duplicated in specific situations.

The only real solution is the following:
Rename the V-Ray materials that don't have a Rhino counterpart (or the Rhino counterpart is of the Custom type).
Then you can reassign them to the scene objects.
This way the duplication issue would be solved since it is caused by identical material names...

We will continue looking into ways to identify and fix the issues causing this in the first place.

Regards,
Konstantin