Overriding context crashes when run from command line #84964

New Issue

Marian Seman · 2021-01-22T15:30:21+01:00

Marian Seman commented

2021-01-22 15:30:21 +01:00

System Information
Operating system: Windows-10-10.0.17134-SP0 64 Bits
Graphics card: Quadro P1000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 452.41

Blender Version
Broken: version: 2.91.2, branch: master, commit date: 2021-01-19 16:15, hash: 5be9ef4177

Short description of error
Using operator with necessary context override ( bpy.ops.mesh.knife_project and bpy.ops.view3d.select_box for me) crashes with EXCEPTION_ACCESS_VIOLATION when trying to run from command line on background.
The same script run directly from Blender is causing no issues. Only using overridden context in operator causes EXCEPTION_ACCESS_VIOLATION, however operator needs overridden context to work correctly. Omitting override results in runtime error as expected.
I was working with Blender version 2.83 when I run into this and issue persisted through update to latest version. When I tested it, I also tried to save .blend file to open on scripting screen directly, to have the same context as when run from blender, but I still got the same error.

Exact steps for others to reproduce the error

Edit provided script (testOverrideCut.py) with path to where .blend file will save on successful run (line 55) - delete if not needed for checking result
Edit path to testOverrideCut.py, err.txt and log.txt in provided command:

blender.exe --background --python C:\tmp\testOverrideCut.py --log-level -1 --debug-all 2> err.txt 1> log.txt

Open Windows command prompt
Run command

testOverrideCut.py

**System Information** Operating system: Windows-10-10.0.17134-SP0 64 Bits Graphics card: Quadro [P1000](https://archive.blender.org/developer/P1000.txt)/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 452.41 **Blender Version** Broken: version: 2.91.2, branch: master, commit date: 2021-01-19 16:15, hash: `5be9ef4177` **Short description of error** Using operator with necessary context override ( bpy.ops.mesh.knife_project and bpy.ops.view3d.select_box for me) crashes with EXCEPTION_ACCESS_VIOLATION when trying to run from command line on background. The same script run directly from Blender is causing no issues. Only using overridden context in operator causes EXCEPTION_ACCESS_VIOLATION, however operator needs overridden context to work correctly. Omitting override results in runtime error as expected. I was working with Blender version 2.83 when I run into this and issue persisted through update to latest version. When I tested it, I also tried to save .blend file to open on scripting screen directly, to have the same context as when run from blender, but I still got the same error. **Exact steps for others to reproduce the error** * Edit provided script (testOverrideCut.py) with path to where .blend file will save on successful run (line 55) - delete if not needed for checking result * Edit path to testOverrideCut.py, err.txt and log.txt in provided command: ``` blender.exe --background --python C:\tmp\testOverrideCut.py --log-level -1 --debug-all 2> err.txt 1> log.txt ``` * Open Windows command prompt * Run command [testOverrideCut.py](https://archive.blender.org/developer/F9592418/testOverrideCut.py) ![image.png](https://archive.blender.org/developer/F9592421/image.png) ![image.png](https://archive.blender.org/developer/F9592426/image.png)

Marian Seman commented

2021-01-22 15:30:21 +01:00

Added subscriber: @mseman

Robert Guetzkow commented

2021-01-22 15:47:25 +01:00

Added subscriber: @rjg

Robert Guetzkow commented

2021-01-22 15:47:25 +01:00

The knife operator requires OpenGL and an active viewport. It does not work in background mode. With the modified context you are forcing it to run, but it fails to do so.

Marian Seman commented

2021-01-22 16:21:15 +01:00

Oh.. I had no idea about this limitation and haven't figured it out from error message. Thanks. So is there a way around this or are all attempts to to run operators that need view_3d window, on batch of .blend files doomed?

blender-admin commented

2021-01-22 19:12:08 +01:00

This issue was referenced by 4792d988fb

This issue was referenced by 4792d988fbaa3a49313f367bc9bb27e889d5d0cf

Germano Cavalcante commented

2021-01-22 19:21:13 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2021-01-22 19:21:13 +01:00

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

Germano Cavalcante self-assigned this 2021-01-22 19:21:13 +01:00

Germano Cavalcante commented

2021-01-22 19:21:14 +01:00

The knife operator has gone through so many changes that it is possible that it no longer needs OpenGL.
If so, this patch would solve the problem:

diff --git a/source/blender/editors/mesh/editmesh_knife.c b/source/blender/editors/mesh/editmesh_knife.c
index f45f48e0e32..2374ff1a7d8 100644
--- a/source/blender/editors/mesh/editmesh_knife.c
+++ b/source/blender/editors/mesh/editmesh_knife.c
@@ -3067,8 +3067,6 @@ void EDBM_mesh_knife(bContext *C, LinkNode *polys, bool use_tag, bool cut_throug
 {
   KnifeTool_OpData *kcd;
 
-  view3d_operator_needs_opengl(C);
-
   /* init */
   {
     const bool only_select = false;

I'm studying the code to see if we can apply the patch without any problems.

(However, I believe there are more convenient ways to achieve the same desired result in the script. Maybe using bmesh operators like bisect_edges, bisect_plane, split).

The knife operator has gone through so many changes that it is possible that it no longer needs OpenGL. If so, this patch would solve the problem: ``` diff --git a/source/blender/editors/mesh/editmesh_knife.c b/source/blender/editors/mesh/editmesh_knife.c index f45f48e0e32..2374ff1a7d8 100644 --- a/source/blender/editors/mesh/editmesh_knife.c +++ b/source/blender/editors/mesh/editmesh_knife.c @@ -3067,8 +3067,6 @@ void EDBM_mesh_knife(bContext *C, LinkNode *polys, bool use_tag, bool cut_throug { KnifeTool_OpData *kcd; - view3d_operator_needs_opengl(C); - /* init */ { const bool only_select = false; ``` I'm studying the code to see if we can apply the patch without any problems. (However, I believe there are more convenient ways to achieve the same desired result in the script. Maybe using bmesh operators like `bisect_edges`, `bisect_plane`, `split`).

Germano Cavalcante commented

2021-01-25 14:12:03 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Germano Cavalcante closed this issue

2021-01-25 14:12:03 +01:00

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Overriding context crashes when run from command line #84964