Can't reproduce here with the specified Blender version.

In T71517#809829, @Philipp Oeser (lichtwerk) wrote:

Also cannot reproduce.

Does this happen with Factory Defaults as well? (File → Defaults → Load Factory Settings)

With or without factory settings, its occuring, just checked.

However, it happens only if both brush selection and Undo is done via shortcut keys. It doesnt happen if I select brush from the menu or use the undo from the menu via mouse or tablet.

Also, just noticed and tested for few minutes. If I assign shortcuts by right clicking on the brushes in the tools sidebar and use those shortcuts, this bug will not occur. Its only occurring if I assign shortcuts from keymap in preferences.

Which shortcuts you are using to select your brush? If you save the file with the brush selected, open it, then sculpt and undo do you have the problem still?

In factory mode, I used the default keys. I just tested with :

• open blender
• preferences -> load factory settings
• new file
• delete everything
• add new cube
• go to sculpt mode
• enable dyntopo
• picked some brush other than draw (inflate in this case)
• did some sculpting
• pressed X to pick draw brush
• sculpted just one stroke
• pressed ctrl-z for undo

At this point, the bug occurs. Stroke disappears but dyntopo turns off.

That also happens if I load the file. I load a file (still in factory settings), pressed X to pick draw brush, made one stroke, ctrl-z for undo. The bug occurred.

Tested on this version also, which is just released : 2.81 (sub 16), branch: master, commit date: 2019-11-12 13:28, hash: rB125257758007

Furthuremore, I can now reproduce bug in a different way. In undo history, anytime I go back to "brush select" or "radial control", the dyntopo gets disabled, regardless of how many strokes I did.

I can reproduce it in win7 550ti gtx following this instructions:

• with factories setting loaded
• activate dyntopo
• Pick another brush than the default draw
• with the new brush selected sculpt some
• here is the main problem: use the shortcut x-key to activate the draw brush sculpt only one stroke and undo. after this dyntopo will be deactivated.

Point to note: if you select the draw brush with mouse selection, you wouldn't see the problem. If you sculpt many stokes with " xkey activated" draw brush, you have to undo all of them before you see Dyntopo deactivated.

In T71517#810119, @Erick Tukuniata (erickblender) wrote:

Point to note: if you select the draw brush with mouse selection, you wouldn't see the problem. If you sculpt many stokes with " xkey activated" draw brush, you have to undo all of them before you see Dyntopo deactivated.

Yeah, it probably has something to do with this bug triggering only when next thing to undo is something other than a brush stroke. And selecting brush by clicking from mouse is not registered as undoable action. But selecting brush by hotkey setup from preferences does, as can be seen by an entry in undo history. It also happens with radial control, because changing brush size etc by radial control does gets registered as undoable action.

Checked in version: 2.81 (sub 16), branch: master, commit date: 2019-11-15 16:32, hash: rBeba4a4bd73ba

Seems to be resolved. Changing brush by keys, or changing brush properties via radial control are no longer registering as undoable actions via sculpting, so the issue of dyntopo turning off mid sculpt is gone.