Fix #114438: wrong undo after running node tool in mesh edit mode #119015

Jacques Lucke · 2024-03-02T22:36:47+01:00

Jacques Lucke commented

2024-03-02 22:36:47 +01:00

I think the issue is that the run-node-group operator overwrites the data stored in the Mesh while mesh edit mode operations typically only change the BMEditMesh. It seems like that causes issues because the mesh edit mode undo stack does not keep track of changes to the Mesh. When hitting undo, Blender assumes that the Mesh stored in the object has not changed and therefore it does not have to be read from the undo step again.

The preliminary fix implemented here is to just not change the Mesh but only the BMEditMesh. This seems to solve the issue.
I haven't quite figured out yet how to tell the undo system that the Mesh has to be loaded from the undo step when undoing out of mesh edit mode. Doing that might provide a better solution.

I think the issue is that the run-node-group operator overwrites the data stored in the `Mesh` while mesh edit mode operations typically only change the `BMEditMesh`. It seems like that causes issues because the mesh edit mode undo stack does not keep track of changes to the `Mesh`. When hitting undo, Blender assumes that the `Mesh` stored in the object has not changed and therefore it does not have to be read from the undo step again. The preliminary fix implemented here is to just not change the `Mesh` but only the `BMEditMesh`. This seems to solve the issue. I haven't quite figured out yet how to tell the undo system that the `Mesh` has to be loaded from the undo step when undoing out of mesh edit mode. Doing that might provide a better solution.

Jacques Lucke added 1 commit 2024-03-02 22:36:57 +01:00

e25aba3d77 fix

Jacques Lucke requested review from Hans Goudey 2024-03-02 22:37:08 +01:00

Hans Goudey requested changes 2024-03-11 21:24:03 +01:00

Dismissed

Hans Goudey left a comment

Thanks, I think this is the best solution for now. I expect edit mode undo will have to change when edit mode doesn't require BMesh, but until then, probably best to avoid changing it.

I think this code should be in editmesh_utils.cc next to EDBM_mesh_make though. Then some of it can be shared and it's less likely that they'll get out of sync.

Thanks, I think this is the best solution for now. I expect edit mode undo will have to change when edit mode doesn't require BMesh, but until then, probably best to avoid changing it. I think this code should be in `editmesh_utils.cc` next to `EDBM_mesh_make` though. Then some of it can be shared and it's less likely that they'll get out of sync.

Jacques Lucke added 2 commits 2024-03-12 11:21:24 +01:00

3404080af9 Merge branch 'blender-v4.1-release' into fix-edit-mode-mesh-undo

1f041cb80b cleanup

Jacques Lucke added 2 commits 2024-03-12 11:34:54 +01:00

b3992be991 cleanup

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