Overriding an armature whose custom property is referenced by a driver in another object creates a duplicate object #100428

Simplified Report

The following file contains an armature with a custom property that enables overrides.
The custom property is referenced by a driver in the modifier of the Plane object.
In a new file, link both objects from the attached file.
Override the plane and its contents.
Override the armature object.
Override the armature data-block.
A new duplicate of the plane is created. Which is the unexpected part.

20220929-134743.mp4

Original Report

System Information
Operating system: Windows-10-10.0.17763-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 512.95

Blender Version
Broken: version: 3.4.0 Alpha, branch: master, commit date: 2022-08-06 22:09, hash: 8b51bd61fd
Worked: 3.2.2, bcfdb14560e7, 2022-08-02 18:15

Short description of error
When there are rig and parented object linked and overriden, the attempt to make override over armature datablock produce a copy of parented object

Exact steps for others to reproduce the error
To reproduce, try same with 3.3 and 3.4
Create new file, link both objects from Rig.blend
Make Library override hierarchy for both,
Rig datablock stays linked.
Try to make Library override hierarchy for it

b3.3 do it properly. b3.4 produce a copy of parented object only if original object was linked. If it wasnt, action do not produce a copy. So there is no way to get rid of unwanted copy and its remove in this case.
Rig.blend

Added subscriber: @Vyach

#101466 was marked as duplicate of this issue

Added subscriber: @lichtwerk

Changed status from 'Needs Triage' to: 'Needs User Info'

Since c73cc15e07, the context menu has changed, could you update your repro steps to reflect that (just to make sure not to confuse others looking at this)
Please use https://builder.blender.org/download/daily/
Please also check if

Rig datablock stays linked.
Try to make Library override hierarchy for it

still applies after said change (seems I cannot reproduce - or I am misunderstanding)

@lichtwerk
Link armature and ball objects from Rig.blend
Select eack and make Library override → create → selected and content
Rig data-block (Alpha-rig) still linked.
Select it, make Library override → create → selected
It produce a copy of ball.

If only armature was linked without a ball, the last action will not produce any ball.
If ball parented to armature in the rig file, this issue will not appear

2022-08-17_01-41-03.mp4

Changed status from 'Needs User Info' to: 'Needs Triage'

Added subscriber: @OmarEmaraDev

Changed status from 'Needs Triage' to: 'Needs User Info'

I remember a similar report, which was classified as a known limitation. The manual says something about this:

Proper Collections Layout Matters

For library overrides to work well, it is much better if all the collections needed by the character are children of the root (linked and instantiated) one, such that there is a clear hierarchy. Otherwise, some data may not be properly automatically overridden, and other operations may be less reliable.

So having two separate objects with no defined hierarchy makes operations less reliable and data might not be automatically overridden as you noted. Does that make sense?

@OmarEmaraDev I am not sure, this is related.
My case is not a character, that can be parented to it`s armature.
My case may be few indipendent objects, and all driven from custom property on the bone.

So object(s) will be duplicated only if they are in the scene.
So blender know somehow, that i need those balls,
but it will nod link em from original scene and will not connect driver to them, if they are already linked.
Blender make copy and then connect drivers…
Very unexpected way. I suppose, it is not «known issue», it just wasn`t tested at all, when overrides were made.

And I expect driver connection to the proper object, not to it`s copied instance.

Rig1.blend
2022-09-18_18-13-07.mp4

Changed status from 'Needs User Info' to: 'Needs Triage'

Changed status from 'Needs Triage' to: 'Confirmed'

Added subscriber: @stephenthomas

Added subscriber: @artutava

Happening on 3.3.1

Added subscriber: @mont29

Changed status from 'Confirmed' to: 'Archived'

As already said, with even link to the manual, this is not expected to work. Blender has absolutely no way to know whether a relation between two linked objects should make them part of the same 'override entity' (aka override hierarchy) or not, unless you clearly group them under a same collection hierarchy, and do link and override these.

I'd ask you to reconsider closing this task. The bug that I reported might show the issue in a way that "should" be expected to work. I bumped up against this issue a lot in a project I'm just finishing up, it's definitely a bug that needs to be looked at/fixed. https://developer.blender.org/T101466

To put it simply, this bug is appearing when new props are being added to an environment file after it has been linked into a shot file. You override in the shot file and unwanted duplicates of the mesh and rig are appearing. This is a very practical/common workflow and the duplicates created are a big issue.

@mont29
I agree with Shephen. If it is should not to work, it shouldn`t work at all, but now it creates duplicates!

That should not be aproblem if you are using collections as intended way to group and link/override sets of related objects. If you directly link the objects, then you are on your own, since Blender does not have the necessary information to handle relationships between these in a useful way.

My bug report was linking collections as intended. Here's a quick screen recording of the bug without any bells and whistles.

duplicate-bug.mp4

The error report that appears at the end reads:

"Data corruption: data-block 'OBAarmature.002' is using another local data-block ('OBArmature.001') as library override reference
Data corruption: data-block 'OBSuzanne.001' is using another local data-block ('OBSuzanne') as library override reference:

OK... but that is completely different from what is described in this task itself... Can you please create a new report only for the case you just describe, including the blend files to reproduce it? Indeed I don't think we really tested the case with several different unrelated rigs in a single linked collection, especially not in resync case (when you edit source collection after having already linked and overridden one in shot file)...

Apologies. My original report showed the error occurring this way and it was merged with this task.

Here's the new report: https://developer.blender.org/T101679

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Overriding an armature whose custom property is referenced by a driver in another object creates a duplicate object #100428

Simplified Report

Original Report