Undo Can Get Stuck If Sculpt Mode Has Been Entered via Undo #84470

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Philip Holzmann · 2021-01-06T19:49:38+01:00

Philip Holzmann commented

2021-01-06 19:49:38 +01:00

System Information
Operating system: Windows 64 bit
Graphics card: Nvidia GTX 750 Ti

Blender Version
Broken: 2.91.0 release, 2.92.0 alpha 9b17e71c23
Worked: ?

Short description of error
With a certain sequence of undo, redo and sculpt operations, part of the mesh can disappear, undo can get "stuck" or the mesh might even change.
They all appear to be triggered by entering the sculpt mode via an undo or redo operation.

(I'm having difficulty reproducing the mesh partially disappearing, so this case is not described here.)

Exact steps for others to reproduce the error
292_sculpt_undo.blend
Open the file.
You are already in Sculpt Mode; Dyntopo is on.

(In this example sequence, the undo will get "stuck" and will need a redo to undo further.)

Sculpt one dab on any face of the cube.
Switch to Object Mode.
Undo. (You are now back in Sculpt Mode, the dab you drew is still there.)
Paint a dab on another face of the cube.
Undo (The second dab disappears.)
Undo again. (Dyntopo is switched off.)
Undo again. (Nothing happens, no matter how often you press it. The first dab is still there.)
Redo. (Nothing happens.)
Undo. (The first dab disappears.)

**System Information** Operating system: Windows 64 bit Graphics card: Nvidia GTX 750 Ti **Blender Version** Broken: 2.91.0 release, 2.92.0 alpha 9b17e71c23a9 Worked: ? **Short description of error** With a certain sequence of undo, redo and sculpt operations, part of the mesh can disappear, undo can get "stuck" or the mesh might even change. They all appear to be triggered by entering the sculpt mode via an undo or redo operation. (I'm having difficulty reproducing the mesh partially disappearing, so this case is not described here.) **Exact steps for others to reproduce the error** [292_sculpt_undo.blend](https://archive.blender.org/developer/F9553410/292_sculpt_undo.blend) Open the file. You are already in Sculpt Mode; Dyntopo is on. (In this example sequence, the undo will get "stuck" and will need a redo to undo further.) 1. Sculpt one dab on any face of the cube. 2. Switch to Object Mode. 3. Undo. *(You are now back in Sculpt Mode, the dab you drew is still there.)* 4. Paint a dab on another face of the cube. 5. Undo *(The second dab disappears.)* 6. Undo again. *(Dyntopo is switched off.)* 7. Undo again. *(Nothing happens, no matter how often you press it. The first dab is still there.)* 8. Redo. *(Nothing happens.)* 9. Undo. *(The first dab disappears.)*

Philip Holzmann commented

2021-01-06 19:49:38 +01:00

Added subscriber: @Foaly

Philip Holzmann commented

2021-01-07 18:43:50 +01:00

I just remembered this one: #80174.
It may be related.

I just remembered this one: #80174. It may be related.

Germano Cavalcante commented

2021-01-07 18:49:58 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2021-01-07 18:49:58 +01:00

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

Germano Cavalcante commented

2021-01-07 18:49:58 +01:00

When trying to reproduce the problem I came across this assert:

BLI_assert failed: C:\Germano\Dev\BlenderDev\blender\source\blender\blenkernel\intern\paint.c:1656, sculpt_update_object(), at 'CustomData_has_layer(&me->pdata, CD_SCULPT_FACE_SETS)'

I don't know if this report is related to other reports involving the sculpt undo system, but as the assert seems to be something new, I am confirming it as a separate report.

@Foaly, when you say "4. Paint a dab on another face of the cube", do you mean using the same "Draw" brush? (I'm not sure if I follow the steps correctly)

When trying to reproduce the problem I came across this assert: ``` BLI_assert failed: C:\Germano\Dev\BlenderDev\blender\source\blender\blenkernel\intern\paint.c:1656, sculpt_update_object(), at 'CustomData_has_layer(&me->pdata, CD_SCULPT_FACE_SETS)' ``` I don't know if this report is related to other reports involving the sculpt undo system, but as the assert seems to be something new, I am confirming it as a separate report. --- @Foaly, when you say `"4. Paint a dab on another face of the cube"`, do you mean using the same "Draw" brush? (I'm not sure if I follow the steps correctly)

Philip Holzmann commented

2021-01-07 21:05:41 +01:00

Yes, just draw with the draw brush.
The things in parentheses are not steps, they are what happens.

Yes, just draw with the draw brush. The things in parentheses are not steps, they are what happens.

Bastien Montagne commented

2021-01-08 16:06:36 +01:00

Added subscriber: @mont29