Deleting Basis Shape Key reverts to previous deleted Shape Key #115194

New Issue

Jens · 2023-11-20T16:52:24+01:00

Jens commented

2023-11-20 16:52:24 +01:00

System Information
Operating system: Linux-5.4.0-166-generic-x86_64-with-glibc2.31 64 Bits, X11 UI
Graphics card: NVIDIA GeForce RTX 2070 SUPER/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 535.129.03
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2070 SUPER/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 536.67

Blender Version
Broken: version: 4.0.1, branch: blender-v4.0-release, commit date: 2023-11-16 16:40, hash: d0dd92834a08
Worked: Unknown

Short description of error
Following the instructions below an Object gets into a state where deleting the only remaining Shape Key "Basis" reverts the Objects Shape to what the previous deleted Shape Key was.
Deleting the "Basis" should not change the Shape.

Exact steps for others to reproduce the error

Duplicate the Default Cube and join both cubes
Create Shape Keys "Basis" and "Key 1" on the Cubes
In Edit Mode, Edit Shape Key 1 on one of both Cubes
Separate the Mesh ob both Cubes into two objects again and join them again.
Now the Object is in the broken state (see attached Blend file).
First delete "Key 1", then delete "Basis". The Object will be in the shape that "Key 1" had.

**System Information** Operating system: Linux-5.4.0-166-generic-x86_64-with-glibc2.31 64 Bits, X11 UI Graphics card: NVIDIA GeForce RTX 2070 SUPER/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 535.129.03 Operating system: Windows-10-10.0.19045-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 2070 SUPER/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 536.67 **Blender Version** Broken: version: 4.0.1, branch: blender-v4.0-release, commit date: 2023-11-16 16:40, hash: `d0dd92834a08` Worked: Unknown **Short description of error** Following the instructions below an Object gets into a state where deleting the only remaining Shape Key "Basis" reverts the Objects Shape to what the previous deleted Shape Key was. Deleting the "Basis" should not change the Shape. **Exact steps for others to reproduce the error** - Duplicate the Default Cube and join both cubes - Create Shape Keys "Basis" and "Key 1" on the Cubes - In Edit Mode, Edit Shape Key 1 on one of both Cubes - Separate the Mesh ob both Cubes into two objects again and join them again. Now the Object is in the broken state (see attached Blend file). - First delete "Key 1", then delete "Basis". The Object will be in the shape that "Key 1" had.

shapekeys-broken-state.crash.txt

3.7 KiB

blender.crash.txt

33 KiB

shapekeys-2023-11-20_16.27.26.mp4

870 KiB

shapekeys-broken-state.blend

106 KiB

Jens added the

labels 2023-11-20 16:52:24 +01:00

Ian Failing commented

2023-11-20 17:29:32 +01:00

Reproduced

System Information
Operating system: Windows-10-10.0.23590-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 4090/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 550.09

Blender Version
Broken: version: 4.0.1, branch: blender-v4.0-release, commit date: 2023-11-16 16:40, hash: d0dd92834a08
Broken: version: 4.1.0 Alpha, branch: main, commit date: 2023-11-18 21:46, hash: 9eba3902c904

Reproduced **System Information** Operating system: Windows-10-10.0.23590-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 4090/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 550.09 **Blender Version** Broken: version: 4.0.1, branch: blender-v4.0-release, commit date: 2023-11-16 16:40, hash: `d0dd92834a08` Broken: version: 4.1.0 Alpha, branch: main, commit date: 2023-11-18 21:46, hash: `9eba3902c904`

Thomas Barlow commented

2023-11-20 19:02:31 +01:00

A mesh's vertex positions and it's 'Basis' shape key positions are stored independently. Certain operations only affect only one of the two which can cause problems. This can be particularly noticeable when removing all shape keys from an object, because the mesh will go back to displaying the mesh's vertex positions instead of its 'Basis' shape key positions.

In this case, when separating (all of Selection, By Material and By Loose Parts are affected), the parts that were separated into new meshes appear to be incorrectly setting their mesh's vertex positions to the vertex positions of the active shape key, when they should be taking the vertex positions from the mesh's vertex positions instead (or maybe even the reference ('Basis') shape key).

This issue with the Separate operators copying the active shape key positions appears to be present even back in Blender 2.79 and 2.80.

Note that entering and exiting edit mode re-syncs a mesh's vertex positions to its 'Basis' shape key.

I suspect that the crash when deleting the shape key from the Outliner is a separate issue that just also happens to be related to using the Separate operators (I could not reproduce the crash in Blender 2.79 and 2.80).

A mesh's vertex positions and it's 'Basis' shape key positions are stored independently. Certain operations only affect only one of the two which can cause problems. This can be particularly noticeable when removing all shape keys from an object, because the mesh will go back to displaying the mesh's vertex positions instead of its 'Basis' shape key positions. In this case, when separating (all of `Selection`, `By Material` and `By Loose Parts` are affected), the parts that were separated into new meshes appear to be incorrectly setting their mesh's vertex positions to the vertex positions of the active shape key, when they should be taking the vertex positions from the mesh's vertex positions instead (or maybe even the reference ('Basis') shape key). This issue with the Separate operators copying the active shape key positions appears to be present even back in Blender 2.79 and 2.80. Note that entering and exiting edit mode re-syncs a mesh's vertex positions to its 'Basis' shape key. --- I suspect that the crash when deleting the shape key from the Outliner is a separate issue that just also happens to be related to using the Separate operators (I could not reproduce the crash in Blender 2.79 and 2.80). --- ![image](/attachments/1e1a544b-46b5-40ab-a259-5b5397ccb326) ![image](/attachments/ddd42672-9480-4370-bbe7-807626cd94c2) ![image](/attachments/f9f93344-9748-459e-82a7-d07ee380c301)

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Richard Antalik commented

2023-11-22 07:14:43 +01:00

Can confirm the crash, that actually seems unrelated as @Mysteryem suggests - I can reproduce that issue with just adding 2 keys and deleting it from outliner.

I can also rerpoduce the reported issue so will confirm

Can confirm the crash, that actually seems unrelated as @Mysteryem suggests - I can reproduce that issue with just adding 2 keys and deleting it from outliner. I can also rerpoduce the reported issue so will confirm

Pratik Borhade commented

2023-11-22 07:22:13 +01:00

Hi, thanks for the report. Can confirm. Re: deleting from outliner, it's a different bug which is being tracked here: #108407

Edit: Had this page open for some time and I missed Richard's comment 😅

Hi, thanks for the report. Can confirm. Re: deleting from outliner, it's a different bug which is being tracked here: #108407 Edit: Had this page open for some time and I missed Richard's comment 😅

Pratik Borhade changed title from ~~Deleting Basis Shape Key reverts to previous deleted Shape Key. Deleting Shape Key in Outliner crashes Blender.~~ to Deleting Basis Shape Key reverts to previous deleted Shape Key

2023-11-22 07:22:28 +01:00

Pratik Borhade added

and removed

labels 2023-11-22 07:23:14 +01:00

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