node.group_ungroup() operator fails to run with correct override context in headless Blender process #115367

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opened 2023-11-24 17:46:06 +01:00 by Ludvik Koutny · 12 comments

Ludvik Koutny commented

2023-11-24 17:46:06 +01:00

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System Information
Operating system: Windows-10-10.0.22621-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 545.84

Blender Version
Broken: version: 4.0.0, branch: blender-v4.0-release, commit date: 2023-11-13 17:26, hash: 878f71061b8e
Worked: (newest version of Blender that worked as expected)

Short description of error
When running operators in headless blender mode like node.group_ungroup() with context override, the operator poll will fail despite the override context being correct.

Steps to reproduce the error

Download and unzip MokeyBatch.zip
Ensure that MonkeyBatch.blend, run_headless.py and batch.py are in the same folder
Open the MonkeyBatch.blend and run run_headless.py from the text editor
Observe the console output, it should print "RuntimeError: Operator bpy.ops.node.group_ungroup.poll() failed, context is incorrect"
Switch text editor to Ungroup text datablock, which contains identical code to batch.py
Run the script and notice the node.group_ungroup() operator works
Result: The operator won't work in headless Blender process despite supplied context override being correct
Expected: The operator runs correctly when the supplied context override is correct

**System Information** Operating system: Windows-10-10.0.22621-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 545.84 **Blender Version** Broken: version: 4.0.0, branch: blender-v4.0-release, commit date: 2023-11-13 17:26, hash: `878f71061b8e` Worked: (newest version of Blender that worked as expected) **Short description of error** When running operators in headless blender mode like node.group_ungroup() with context override, the operator poll will fail despite the override context being correct. **Steps to reproduce the error** 1. Download and unzip MokeyBatch.zip 2. Ensure that MonkeyBatch.blend, run_headless.py and batch.py are in the same folder 3. Open the MonkeyBatch.blend and run run_headless.py from the text editor 4. Observe the console output, it should print "RuntimeError: Operator bpy.ops.node.group_ungroup.poll() failed, context is incorrect" 5. Switch text editor to Ungroup text datablock, which contains identical code to batch.py 6. Run the script and notice the node.group_ungroup() operator works Result: The operator won't work in headless Blender process despite supplied context override being correct Expected: The operator runs correctly when the supplied context override is correct

MonkeyBatch.zip

132 KiB

Ludvik Koutny added the

labels 2023-11-24 17:46:07 +01:00

Iliya Katushenock added the

Nodes & Physics

labels 2023-11-24 17:55:47 +01:00

Thomas Barlow commented

2023-11-24 18:15:22 +01:00

Member

The script only fails on the last line for me where the context isn't overridden, which I would have expected since the current context will be the Text Editor. The operator call within the context override on line 26 works fine.

The script only fails on the last line for me where the context isn't overridden, which I would have expected since the current context will be the Text Editor. The operator call within the context override on line 26 works fine.

Ludvik Koutny commented

2023-11-24 18:34:41 +01:00

Author

Contributor

The script only fails on the last line for me where the context isn't overridden, which I would have expected since the current context will be the Text Editor. The operator call within the context override on line 26 works fine.

Huh, you are totally right... I hastily put this file together because bug reports require simplified examples, so I missed this. I can make it work in the simplified file, but I still can't make it work in my addon which runs headless Blender :(

I know this is probably too much to ask but could you by any chance figure out what I am doing wrong in my addon? The addon is relatively small (about 400 lines out of which only about 50 are relevant to this). I am even willing to pay you for your time. I am doing literally the same thing as in this small repro file, but in my addon it doesn't work.

I am attaching the addon file, and if you install the addon (feel free to check the source code beforehand), then you can just open the .blend file in Monkeys.zip, set the bake output path on the sidebar panel to a valid folder, and click the "Bake Collection PBR" button in the LK Bake Toolkit sidebar. It will call very short and simple LK_BAKE_TOOLKIT_OT_submit_bake operator in init.py which launches blender instance which runs bake.py where the culprit code is on lines 19-45.

Thanks in advance.

> The script only fails on the last line for me where the context isn't overridden, which I would have expected since the current context will be the Text Editor. The operator call within the context override on line 26 works fine. Huh, you are totally right... I hastily put this file together because bug reports require simplified examples, so I missed this. I can make it work in the simplified file, but I still can't make it work in my addon which runs headless Blender :( I know this is probably too much to ask but could you by any chance figure out what I am doing wrong in my addon? The addon is relatively small (about 400 lines out of which only about 50 are relevant to this). I am even willing to pay you for your time. I am doing literally the same thing as in this small repro file, but in my addon it doesn't work. I am attaching the addon file, and if you install the addon (feel free to check the source code beforehand), then you can just open the .blend file in Monkeys.zip, set the bake output path on the sidebar panel to a valid folder, and click the "Bake Collection PBR" button in the LK Bake Toolkit sidebar. It will call very short and simple LK_BAKE_TOOLKIT_OT_submit_bake operator in __init__.py which launches blender instance which runs bake.py where the culprit code is on lines 19-45. Thanks in advance.

lk_bake_toolkit_4.0.zip

5.6 KiB

Monkeys.zip

166 KiB

Ludvik Koutny commented

2023-11-24 21:21:42 +01:00

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Contributor

I am getting even more confused here.

When launching Blender in headless mode, the exact same script will fail the first time and then run fine the second time. I am slowly going crazy.

Just running the identical script second time works... O_o

EDIT: It appears to work when the supplied NODE_EDITOR area already exists in the UI, but it will fail if other area is converted to NODE_EDITOR area during the same operation 🤔

I am getting even more confused here. When launching Blender in headless mode, the exact same script will fail the first time and then run fine the second time. I am slowly going crazy. <video src="/attachments/9ffdccfa-a317-4606-9db2-f4ff87210611" title="2023-11-24_21-20-42.mp4" controls></video> Just running the identical script second time works... O_o EDIT: It appears to work when the supplied NODE_EDITOR area already exists in the UI, but it will fail if other area is converted to NODE_EDITOR area during the same operation 🤔

2023-11-24_21-20-42.mp4

18 MiB

Ludvik Koutny changed title from ~~node.group_ungroup() operator doesn't work with context override~~ to context override fails on some operators if executed too soon

2023-11-24 22:04:42 +01:00

Germano Cavalcante commented

2023-11-25 14:20:32 +01:00

Member

At first glance, it doesn't look like a bug. You are changing the area type in:
area.type = 'NODE_EDITOR'

It's important to request a UI update to ensure that this change takes effect.

Does this make sense to you?

At first glance, it doesn't look like a bug. You are changing the area type in: `area.type = 'NODE_EDITOR'` It's important to request a UI update to ensure that this change takes effect. Does this make sense to you?

Germano Cavalcante added

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labels 2023-11-25 14:20:44 +01:00

Ludvik Koutny commented

2023-11-25 14:30:30 +01:00

Author

Contributor

At first glance, it doesn't look like a bug. You are changing the area type in:
area.type = 'NODE_EDITOR'

It's important to request a UI update to ensure that this change takes effect.

Does this make sense to you?

Not sure, I would like to try it and see if it works? What's the proper way to request UI update? There doesn't seem to be any documentation on it. I can make it work if I spawn blender process with UI, but once I pass the '-b' argument, to run Blender without UI, even that bpy.ops.wm.redraw_timer(type='DRAW_WIN_SWAP', iterations=1) workaround stops working.

> At first glance, it doesn't look like a bug. You are changing the area type in: > `area.type = 'NODE_EDITOR'` > > It's important to request a UI update to ensure that this change takes effect. > > Does this make sense to you? Not sure, I would like to try it and see if it works? What's the proper way to request UI update? There doesn't seem to be any documentation on it. I can make it work if I spawn blender process with UI, but once I pass the '-b' argument, to run Blender without UI, even that bpy.ops.wm.redraw_timer(type='DRAW_WIN_SWAP', iterations=1) workaround stops working.

Germano Cavalcante commented

2023-11-25 15:06:09 +01:00

Member

What's the proper way to request UI update?

I don't remember off the top of my head. scene.update or something like that...
But generally having to change the interface to execute a command is not conventinal (this is more common to test something).

For assistance I suggest to ask on one of the community websites: https://www.blender.org/community/

> What's the proper way to request UI update? I don't remember off the top of my head. scene.update or something like that... But generally having to change the interface to execute a command is not conventinal (this is more common to test something). For assistance I suggest to ask on one of the community websites: https://www.blender.org/community/

Ludvik Koutny commented

2023-11-25 15:08:34 +01:00

Author

Contributor

What's the proper way to request UI update?

I don't remember off the top of my head. scene.update or something like that...
But generally having to change the interface to execute a command is not conventinal (this is more common to test something).

For assistance I suggest to ask on one of the community websites: https://www.blender.org/community/

I would like to close this too, if this is not a bug, but I still want to ensure it's not one, because, I really spent a lot of time trying various things and context override just won't work in headless Blender process, while the exact same code does work in regular Blender and even in spawned subprocess with UI enabled.

Just to be sure... if it wasn't possible to run bpy.ops.node.group_ungroup() operator in headless Blender (using the '-b' argument) under any circumstances, would that be considered a bug?

> > What's the proper way to request UI update? > > I don't remember off the top of my head. scene.update or something like that... > But generally having to change the interface to execute a command is not conventinal (this is more common to test something). > > For assistance I suggest to ask on one of the community websites: https://www.blender.org/community/ I would like to close this too, if this is not a bug, but I still want to ensure it's not one, because, I really spent a lot of time trying various things and context override just won't work in headless Blender process, while the exact same code does work in regular Blender and even in spawned subprocess with UI enabled. Just to be sure... if it wasn't possible to run bpy.ops.node.group_ungroup() operator in headless Blender (using the '-b' argument) under any circumstances, would that be considered a bug?

Ludvik Koutny changed title from ~~context override fails on some operators if executed too soon~~ to node.group_ungroup() operator fails to run with correct override context in headless Blender process

2023-11-25 15:56:06 +01:00

Ludvik Koutny commented

2023-11-25 16:06:47 +01:00

Author

Contributor

@mano-wii I have spent lots of time making really good repro file. I have updated the report description to be concise and I've uploaded a new package which should make it really easy to reproduce it.

I don't remember off the top of my head. scene.update or something like that...
But generally having to change the interface to execute a command is not conventinal (this is more common to test something).

Regarding this, do you have any better idea how to run node.group_ungroup() which requires node editor area to be run? I can't make assumption that there's a shader editor already existing somewhere in the UI as users can customize their startup .blend file.

@mano-wii I have spent lots of time making really good repro file. I have updated the report description to be concise and I've uploaded a new package which should make it really easy to reproduce it. > I don't remember off the top of my head. scene.update or something like that... > But generally having to change the interface to execute a command is not conventinal (this is more common to test something). Regarding this, do you have any better idea how to run node.group_ungroup() which requires node editor area to be run? I can't make assumption that there's a shader editor already existing somewhere in the UI as users can customize their startup .blend file.

Ludvik Koutny commented

2023-11-25 17:07:28 +01:00

Author

Contributor

I tried another approach, where I created a blend file that has only one workspace with one area, and that area is NODE_EDITOR. I then load this blender file during the startup of headless blender. The print(context.screen.areas[0].type) returns NODE_EDITOR so this area already exists, and is not being changed to from another area. I then do following:

        print(context.screen.areas[0].type)

        node_groups = [node for node in node_tree.nodes if node.type == 'GROUP']

        context_override = context.copy()

        context_override['area'] = context.screen.areas[0]
        context_override['region'] = context.screen.areas[0].regions[-1]
        context_override['space_data'] = context.screen.areas[0].spaces.active

        context_override['active_node'] = node_groups[0]
        context_override['material'] = material
        context_override['selected_nodes'] = node_groups

        with context.temp_override(**context_override):
            bpy.ops.node.group_ungroup()

And the result is same:
RuntimeError: Operator bpy.ops.node.group_ungroup.poll() failed, context is incorrect

This must be bugged... Even when I ensure the NODE_EDITOR area already exists, the operator still considers the context incorrect.

I tried another approach, where I created a blend file that has only one workspace with one area, and that area is NODE_EDITOR. I then load this blender file during the startup of headless blender. The print(context.screen.areas[0].type) returns NODE_EDITOR so this area already exists, and is not being changed to from another area. I then do following: ``` print(context.screen.areas[0].type) node_groups = [node for node in node_tree.nodes if node.type == 'GROUP'] context_override = context.copy() context_override['area'] = context.screen.areas[0] context_override['region'] = context.screen.areas[0].regions[-1] context_override['space_data'] = context.screen.areas[0].spaces.active context_override['active_node'] = node_groups[0] context_override['material'] = material context_override['selected_nodes'] = node_groups with context.temp_override(**context_override): bpy.ops.node.group_ungroup() ``` And the result is same: RuntimeError: Operator bpy.ops.node.group_ungroup.poll() failed, context is incorrect This must be bugged... Even when I ensure the NODE_EDITOR area already exists, the operator still considers the context incorrect.

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labels 2023-11-25 17:09:04 +01:00

JerryMei commented

2024-01-27 09:22:13 +01:00

I have facing similar problem with group_ungroup! The issue is to make sure b61496c508/source/blender/editors/space_node/node_group.cc (L88) evaluted to be true

I have facing similar problem with group_ungroup! The issue is to make sure https://github.com/blender/blender/blob/b61496c5089260a5a35ed4863685ef072e7c5e79/source/blender/editors/space_node/node_group.cc#L88 evaluted to be true

Pratik Borhade commented

2024-03-20 07:11:22 +01:00

Member

HI, thanks for the report. Can confirm. Instead of with context.temp_override(**context_override): following might work but not sure how correct this is:

for window in context.window_manager.windows:
    for area in window.screen.areas:
        if area.type == 'NODE_EDITOR':
            with context.temp_override(window=window, area=area):
                bpy.ops.node.group_ungroup()

@ideasman42 , can you check if the script mentioned in the report is valid/supported case?

HI, thanks for the report. Can confirm. Instead of `with context.temp_override(**context_override):` following might work but not sure how correct this is: ``` for window in context.window_manager.windows: for area in window.screen.areas: if area.type == 'NODE_EDITOR': with context.temp_override(window=window, area=area): bpy.ops.node.group_ungroup() ``` @ideasman42 , can you check if the script mentioned in the report is valid/supported case?

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Pratik Borhade commented

2024-03-20 07:23:27 +01:00

Member

Ah, my change won't work since the other instance is launched in background mode (no window) :)

It didn't throw the context error so I assumed it's working

Ah, my change won't work since the other instance is launched in background mode (no window) :) It didn't throw the context error so I assumed it's working

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