Outliner: Linking object hierachies to a collection is buggy #90165

New Issue

Debuk · 2021-07-26T14:10:16+02:00

Debuk commented

2021-07-26 14:10:16 +02:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: Radeon RX Vega ATI Technologies Inc. 4.5.14830 Core Profile Context 21.4.1 27.20.21002.112

Blender Version
Broken: version: 2.93.2 Release Candidate, branch: master, commit date: 2021-07-07 05:52, hash: 9e64fd461a
Worked: Unknown
Linking objects with parent child relationship has inconsistent display behaviour in outliner

Short description of error
This bugreport is about linking an object in the outliner to an additional collection.

A linked object can have children. Normally they are displayed in a greyed out state until they are also linked to the same collection as the parent. But there is a bug or at least an inconsistent behaviour if these childs are displayed in a greyed out state or not at all.

Exact steps for others to reproduce the error

The following script adds 3 cubes ,creates a collection and links the cubes to it.
I deleted everything from the Scene Collection and did run the script.

This will work:

But just one more child-level in the tree and it starts to behave inconsistent as can be seen in the outliner shown in the screenshot of some reruns of the same script on a totally empty scene.


import bpy

# create some cubes
bpy.ops.mesh.primitive_cube_add(location=(0,0,0))
cube0= bpy.context.active_object
bpy.ops.mesh.primitive_cube_add(location=(5,0,0))
cube1= bpy.context.active_object
bpy.ops.mesh.primitive_cube_add(location=(10,0,0))
cube2= bpy.context.active_object
bpy.ops.mesh.primitive_cube_add(location=(10,0,0))
cube3= bpy.context.active_object

#create a new coll
collection = bpy.data.collections.new("Test")
bpy.context.scene.collection.children.link(collection)

# establish parent child relationships

cube1.parent = cube0
cube2.parent = cube1
cube3.parent = cube2

# link root cube to new coll
collection.objects.link(cube0)

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: Radeon RX Vega ATI Technologies Inc. 4.5.14830 Core Profile Context 21.4.1 27.20.21002.112 **Blender Version** Broken: version: 2.93.2 Release Candidate, branch: master, commit date: 2021-07-07 05:52, hash: `9e64fd461a` Worked: Unknown Linking objects with parent child relationship has inconsistent display behaviour in outliner **Short description of error** This bugreport is about linking an object in the outliner to an additional collection. A linked object can have children. Normally they are displayed in a greyed out state until they are also linked to the same collection as the parent. But there is a bug or at least an inconsistent behaviour if these childs are displayed in a greyed out state or not at all. **Exact steps for others to reproduce the error** The following script adds 3 cubes ,creates a collection and links the cubes to it. I deleted everything from the Scene Collection and did run the script. This will work: ![Working.jpg](https://archive.blender.org/developer/F10238409/Working.jpg) But just one more child-level in the tree and it starts to behave inconsistent as can be seen in the outliner shown in the screenshot of some reruns of the same script on a totally empty scene. ![Bug.jpg](https://archive.blender.org/developer/F10238411/Bug.jpg) ![Bug2.jpg](https://archive.blender.org/developer/F10238413/Bug2.jpg) ![Bug3.jpg](https://archive.blender.org/developer/F10238415/Bug3.jpg) ``` import bpy # create some cubes bpy.ops.mesh.primitive_cube_add(location=(0,0,0)) cube0= bpy.context.active_object bpy.ops.mesh.primitive_cube_add(location=(5,0,0)) cube1= bpy.context.active_object bpy.ops.mesh.primitive_cube_add(location=(10,0,0)) cube2= bpy.context.active_object bpy.ops.mesh.primitive_cube_add(location=(10,0,0)) cube3= bpy.context.active_object #create a new coll collection = bpy.data.collections.new("Test") bpy.context.scene.collection.children.link(collection) # establish parent child relationships cube1.parent = cube0 cube2.parent = cube1 cube3.parent = cube2 # link root cube to new coll collection.objects.link(cube0) ```

Debuk commented

2021-07-26 14:10:16 +02:00

Added subscriber: @Debuk

Philipp Oeser commented

2021-07-26 17:11:30 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-07-26 17:11:30 +02:00

Can confirm.

Philipp Oeser commented

2021-07-26 17:11:41 +02:00

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

Philipp Oeser changed title from ~~Linking object hierachies to a collection is buggy~~ to Outliner: Linking object hierachies to a collection is buggy (via script, if run more than once)

2021-07-26 17:12:11 +02:00

Debuk commented

2021-07-26 18:45:22 +02:00

Can confirm.

Thanks @lichtwerk , just a note as I think the renamed title is a bit misleading now. The scripts shows the inconsistency of the operations , but its not just happening that way. Creating the objects, collections, the parenting and linking can all be done manually and will also fail.

And the script also does often fail in the first run.

Heres a screenshot of a manual creation

> Can confirm. Thanks @lichtwerk , just a note as I think the renamed title is a bit misleading now. The scripts shows the inconsistency of the operations , but its not just happening that way. Creating the objects, collections, the parenting and linking can all be done manually and will also fail. And the script also does often fail in the first run. Heres a screenshot of a manual creation ![Manually.jpg](https://archive.blender.org/developer/F10238900/Manually.jpg)

Philipp Oeser commented

2021-07-26 21:11:03 +02:00

Hm, weird, I was testing this manually as well and it didnt happen then.
If I repro the steps exactly as in the script, it happens manually for me as well (so assume there is a difference if one of the cubes is in the collection already).
Will change the title back.

Hm, weird, I was testing this manually as well and it didnt happen then. If I repro the steps exactly as in the script, it happens manually for me as well (so assume there is a difference if one of the cubes is in the collection already). Will change the title back.

Philipp Oeser changed title from ~~Outliner: Linking object hierachies to a collection is buggy (via script, if run more than once)~~ to Outliner: Linking object hierachies to a collection is buggy

2021-07-26 21:11:12 +02:00

Debuk commented

2021-07-26 22:04:15 +02:00

Ok, yes I see, its simply not happening everytime, thats why its easier reproduced by script. If the depthlevels of the unlinked hierarchy displayed is less or equal to 2 it seems to work. If its more most times it fails.

Daniele De Luca commented

2021-12-01 23:58:21 +01:00

Added subscriber: @Sparazza

Daniele De Luca commented

2021-12-02 00:14:03 +01:00

Also confirm.. I've seen the same behaviour while creating a 3 object hierarchy, having some into a collection and the others in another collection. I think is related to the same linking problem.
By reloading the file a bunch of times, the inner children will be shown out from the parent relation (at random).

I've made a video of the issue with a brand new file:
Bug Outliner Parent Link-1.mp4
Sorry for the jumping video.. but you can clearly see at every reload of the scene that Son and Daughter jumps off from the father into the outliner.

Also confirm.. I've seen the same behaviour while creating a 3 object hierarchy, having some into a collection and the others in another collection. I think is related to the same linking problem. By reloading the file a bunch of times, the inner children will be shown out from the parent relation (at random). I've made a video of the issue with a brand new file: [Bug Outliner Parent Link-1.mp4](https://archive.blender.org/developer/F12676200/Bug_Outliner_Parent_Link-1.mp4) Sorry for the jumping video.. but you can clearly see at every reload of the scene that Son and Daughter jumps off from the father into the outliner.

Philipp Oeser removed the

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Outliner: Linking object hierachies to a collection is buggy #90165