Loop cut geometry movement gets undone by shape keys unless edit mode is toggled #122595

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sap-1 · 2024-06-01T13:54:30+02:00

sap-1 commented

2024-06-01 13:54:30 +02:00

System Information
Operating system: Linux-6.9.1-arch1-1-x86_64-with-glibc2.39 64 Bits, WAYLAND UI
Graphics card: AMD Radeon RX 7900 XTX (radeonsi, navi31, LLVM 17.0.6, DRM 3.57, 6.9.1-arch1-1) AMD 4.6 (Core Profile) Mesa 24.0.7-arch1.3

Blender Version
Broken: version: 4.2.0 Alpha, branch: main, commit date: 2024-05-31 20:55, hash: 0d7d6b00c9ec
Worked: maybe never? Also fails in 3.3

Short description of error
Sometimes when making a model I need to add more geometry to some regions by adding loop cuts. If my mesh has shape keys then I often get strange and inconsistent results. It seems that if you add a loop cut and move or slide the new geometry without exiting edit mode in-between, all shape keys will now undo the move/slide.

I find this quite unexpected, I'm not sure if it's supposed to be a feature, it would always catch me by surprise and mess up a lot of my shape keys

Exact steps for others to reproduce the error

Open default scene
Add 4-5 shape keys, select basis
Switch to edit mode -> add loop cut (confirm the operation)
Ctrl E -> edge slide
Exit edit mode
Increase the shape key weights, it will move the new loop upwards.

Expected behavior:
Do the same but only do a loop cut without sliding, then exit edit mode, then enter edit mode again and slide it down 75% separately, and the behavior changes - the shape keys now have no effect (which is what I would expect)

See a demonstration here: https://youtu.be/G1uQ7ubqi7w

**System Information** Operating system: Linux-6.9.1-arch1-1-x86_64-with-glibc2.39 64 Bits, WAYLAND UI Graphics card: AMD Radeon RX 7900 XTX (radeonsi, navi31, LLVM 17.0.6, DRM 3.57, 6.9.1-arch1-1) AMD 4.6 (Core Profile) Mesa 24.0.7-arch1.3 **Blender Version** Broken: version: 4.2.0 Alpha, branch: main, commit date: 2024-05-31 20:55, hash: `0d7d6b00c9ec` Worked: maybe never? Also fails in 3.3 **Short description of error** Sometimes when making a model I need to add more geometry to some regions by adding loop cuts. If my mesh has shape keys then I often get strange and inconsistent results. It seems that if you add a loop cut and move or slide the new geometry without exiting edit mode in-between, all shape keys will now undo the move/slide. I find this quite unexpected, I'm not sure if it's supposed to be a feature, it would always catch me by surprise and mess up a lot of my shape keys **Exact steps for others to reproduce the error** - Open default scene - Add 4-5 shape keys, select basis - Switch to edit mode -> add loop cut (confirm the operation) - `Ctrl E -> edge slide` - Exit edit mode - Increase the shape key weights, it will move the new loop upwards. Expected behavior: Do the same but only do a loop cut without sliding, then exit edit mode, then enter edit mode again and slide it down 75% separately, and the behavior changes - the shape keys now have no effect (which is what I would expect) See a demonstration here: https://youtu.be/G1uQ7ubqi7w

sap-1 added the

labels 2024-06-01 13:54:30 +02:00

Pratik Borhade commented

2024-06-03 11:32:43 +02:00

Thanks for the report. Can confirm

Pratik Borhade added