Regression: Deleting Objects in a View Layer leaves None in the View Layer's .objects for the script duration #113378

New Issue

Thomas Barlow · 2023-10-07T02:05:20+02:00

Thomas Barlow commented

2023-10-07 02:05:20 +02:00

System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 536.40

Blender Version
Broken: version: 3.4.0, branch: blender-v3.4-release, commit date: 2022-12-06 18:46, hash: a95bf1ac01be, also version: 3.6.4, version 4.0.0b 2023-09-28 00:03, hash: 751c9ef620a0 and version 4.1.0a 2023-10-05, hash: c68f568eb305
Worked: version: 3.3.11

Short description of error
Deleting one or more Objects that are in a ViewLayer leaves a single None entry in that ViewLayer's .objects for the remaining duration of the script.

This only seems to affect ViewLayer.objects.
Scene.objects and Collection.objects work as expected.

This broke part of a community addon that assumed ViewLayer.objects would only ever contain Object instances.

3.3.11 and older	3.4.0 and newer

Exact steps for others to reproduce the error

import bpy

context = bpy.context

for o in context.view_layer.objects:
    print(list(context.view_layer.objects))
    bpy.data.objects.remove(o)
print("view layer objects after deletion:")
print(len(context.view_layer.objects))
print(list(context.view_layer.objects))

Ensure there is at least one Object in the current view layer
Open the System Console to be able to observe the script output
Run the above script
Observe that, in 3.4.0+, after removing an Object, context.view_layer.objects contains a None element
Run the above script again
Observe that context.view_layer.objects is now empty as expected

**System Information** Operating system: Windows-10-10.0.19045-SP0 64 Bits Graphics card: NVIDIA GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 536.40 **Blender Version** Broken: version: 3.4.0, branch: blender-v3.4-release, commit date: 2022-12-06 18:46, hash: `a95bf1ac01be`, also version: 3.6.4, version 4.0.0b 2023-09-28 00:03, hash: `751c9ef620a0` and version 4.1.0a 2023-10-05, hash: `c68f568eb305` Worked: version: 3.3.11 **Short description of error** Deleting one or more Objects that are in a ViewLayer leaves a single `None` entry in that ViewLayer's .objects for the remaining duration of the script. This only seems to affect `ViewLayer.objects`. `Scene.objects` and `Collection.objects` work as expected. This broke part of a community addon that assumed `ViewLayer.objects` would only ever contain `Object` instances. | 3.3.11 and older | 3.4.0 and newer | | -- | -- | | ![image](/attachments/ad90d3e2-3e42-44d9-b2fa-288099e1c2c9) | ![image](/attachments/eb994f00-e376-4b3f-90fd-3cf7a1067c05) | **Exact steps for others to reproduce the error** ```py import bpy context = bpy.context for o in context.view_layer.objects: print(list(context.view_layer.objects)) bpy.data.objects.remove(o) print("view layer objects after deletion:") print(len(context.view_layer.objects)) print(list(context.view_layer.objects)) ``` 1. Ensure there is at least one Object in the current view layer 2. Open the System Console to be able to observe the script output 3. Run the above script 4. Observe that, in 3.4.0+, after removing an Object, `context.view_layer.objects` contains a `None` element 5. Run the above script again 6. Observe that `context.view_layer.objects` is now empty as expected

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Thomas Barlow added the

labels 2023-10-07 02:05:21 +02:00

Thomas Barlow commented

2023-10-07 05:30:30 +02:00

Perhaps of note is if I instead use the experimental bpy.data.batch_remove() to delete the Objects in the View Layer it replaces each Object with None in 3.4.0 and newer rather than leaving a single None element:

import bpy

context = bpy.context

bpy.data.batch_remove(context.view_layer.objects)
print("view layer objects after deletion:")
print(len(context.view_layer.objects))
print(list(context.view_layer.objects))

In 3.3.11, view_layer.objects will immediately be empty, as expected, when using bpy.data.batch_remove() to delete all the Objects, just like when using bpy.data.objects.remove().

Perhaps of note is if I instead use the experimental `bpy.data.batch_remove()` to delete the Objects in the View Layer it replaces each Object with `None` in 3.4.0 and newer rather than leaving a single `None` element: ```py import bpy context = bpy.context bpy.data.batch_remove(context.view_layer.objects) print("view layer objects after deletion:") print(len(context.view_layer.objects)) print(list(context.view_layer.objects)) ``` ![image](/attachments/21a15383-88ba-4d7a-8fae-91ebc5a09037) In 3.3.11, `view_layer.objects` will immediately be empty, as expected, when using `bpy.data.batch_remove()` to delete all the Objects, just like when using `bpy.data.objects.remove()`.

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Philipp Oeser commented

2023-10-09 10:42:41 +02:00

Note that a simple bpy.context.view_layer.update() can solve the issue, still, will check when behavior changed

Note that a simple `bpy.context.view_layer.update()` can solve the issue, still, will check when behavior changed

Pratik Borhade commented

2023-10-11 07:43:49 +02:00

I can confirm

Pratik Borhade added

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Regression: Deleting Objects in a View Layer leaves None in the View Layer's .objects for the script duration #113378