Crash when evaluating ghostly edge #109803

New Issue

Jonathan Lampel · 2023-07-07T03:31:35+02:00

Jonathan Lampel commented

2023-07-07 03:31:35 +02:00

System Information
Operating system: Windows-10-10.0.18363-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 528.24

Blender Version
Broken: version: 3.6.0, branch: blender-v3.6-release, commit date: 2023-06-27 08:08, hash: c7fc78b81ecb
Worked: unknown

Short description of error
Possibly one of the strangest bugs I've seen. No idea how the mesh was generated (not mine), but there is an edge that appears to both exist as a side of two faces but not exist as an edge. The two faces appear as an n-gon when in vertex and edge select mode but not in face select mode. Blender crashes hard whenever an edge action is performed on the two connecting vertices. Re-sorting the mesh elements fixes the problem.

Exact steps for others to reproduce the error

Open the provided file and look at the two selected faces
Select the two vertices connecting the "edge" which separates the two faces
Notice the selection highlight in wireframe view also highlights other vertices in the back, hinting that it's a vertex order problem
Hit J to connect the two vertices in question
Crash
Try again, but this time recalculate the vertex order beforehand, and the edge will appear correctly

**System Information** Operating system: Windows-10-10.0.18363-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 528.24 **Blender Version** Broken: version: 3.6.0, branch: blender-v3.6-release, commit date: 2023-06-27 08:08, hash: `c7fc78b81ecb` Worked: unknown **Short description of error** Possibly one of the strangest bugs I've seen. No idea how the mesh was generated (not mine), but there is an edge that appears to both exist as a side of two faces but not exist as an edge. The two faces appear as an n-gon when in vertex and edge select mode but not in face select mode. Blender crashes hard whenever an edge action is performed on the two connecting vertices. Re-sorting the mesh elements fixes the problem. **Exact steps for others to reproduce the error** 1. Open the provided file and look at the two selected faces 2. Select the two vertices connecting the "edge" which separates the two faces 3. Notice the selection highlight in wireframe view also highlights other vertices in the back, hinting that it's a vertex order problem 4. Hit J to connect the two vertices in question 5. Crash 6. Try again, but this time recalculate the vertex order beforehand, and the edge will appear correctly

Screenshot 2023-07-06 183127.png

157 KiB

uvf_crash_003.blend

986 KiB

Jonathan Lampel added the

labels 2023-07-07 03:31:35 +02:00

YimingWu commented

2023-07-07 05:28:23 +02:00

This mesh contains invalid data. Use bpy.context.object.data.validate(verbose=True) in blender scripting gives following result in system terminal:

Not sure why it does, you probably need to investigate how the mesh is generated to get a better idea.

ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:594 BKE_mesh_validate_arrays: 	Poly 470 has duplicated vert reference at corner (1)
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:594 BKE_mesh_validate_arrays: 	Poly 472 has duplicated vert reference at corner (3)
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:594 BKE_mesh_validate_arrays: 	Poly 473 has duplicated vert reference at corner (3)
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:745 BKE_mesh_validate_arrays: 	Loop 1866 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:745 BKE_mesh_validate_arrays: 	Loop 1867 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:745 BKE_mesh_validate_arrays: 	Loop 1868 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:745 BKE_mesh_validate_arrays: 	Loop 1869 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: 	Loop 1874 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: 	Loop 1875 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: 	Loop 1876 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: 	Loop 1877 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: 	Loop 1878 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: 	Loop 1879 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: 	Loop 1880 is unused.
ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: 	Loop 1881 is unused.

Will close the issue for now since this is caused by invalid mesh, not blender itself. If you managed to find a way to create such invalid mesh topology in blender, please feel free to add more information. Thanks!

This mesh contains invalid data. Use `bpy.context.object.data.validate(verbose=True)` in blender scripting gives following result in system terminal: Not sure why it does, you probably need to investigate how the mesh is generated to get a better idea. ``` ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:594 BKE_mesh_validate_arrays: Poly 470 has duplicated vert reference at corner (1) ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:594 BKE_mesh_validate_arrays: Poly 472 has duplicated vert reference at corner (3) ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:594 BKE_mesh_validate_arrays: Poly 473 has duplicated vert reference at corner (3) ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:745 BKE_mesh_validate_arrays: Loop 1866 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:745 BKE_mesh_validate_arrays: Loop 1867 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:745 BKE_mesh_validate_arrays: Loop 1868 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:745 BKE_mesh_validate_arrays: Loop 1869 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: Loop 1874 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: Loop 1875 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: Loop 1876 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: Loop 1877 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: Loop 1878 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: Loop 1879 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: Loop 1880 is unused. ERROR (bke.mesh): source/blender/blenkernel/intern/mesh_validate.cc:780 BKE_mesh_validate_arrays: Loop 1881 is unused. ``` Will close the issue for now since this is caused by invalid mesh, not blender itself. If you managed to find a way to create such invalid mesh topology in blender, please feel free to add more information. Thanks!

YimingWu closed this issue

2023-07-07 05:28:25 +02:00

Blender Bot added

and removed

labels 2023-07-07 05:28:28 +02:00

YimingWu added the

Module

Modeling

label 2023-07-07 05:28:36 +02:00

Jonathan Lampel commented

2023-07-07 07:26:58 +02:00

I mean, Blender is allowing it to exist, so I figured there could be a check, or the mesh could be recalculated when an invalid configuration is detected, or something to avoid a hard crash. I'll add more info if I ever figure out how to generate a mesh like this. Thanks for looking into it.

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Crash when evaluating ghostly edge #109803