mirror vertex groups command is always flipping weights #98450

New Issue

Silas Wittwer · 2022-05-27T18:06:48+02:00

Silas Wittwer commented

2022-05-27 18:06:48 +02:00

System Information
Operating system: WIN 11
Graphics card: RTX 3090

Blender Version
Broken: (example: 3.1.2, cc66d1020c, master)
Worked: (newest version of Blender that worked as expected)

Short description of error
"mirror vertex groups (topology)" and "mirror vertex groups" command is always flipping weights instead of mirroring. See attached video. 2022-05-27 17-55-22.mkv

Expected behavior
When one bone is selected > mirror weight to the corresponding bone on the other side.
When two corresponding bones are selected > flip weight of selected bones

Exact steps for others to reproduce the error

Open attached blend file
Select armature and mesh
Go to weight paint mode
Select bone: CC_Base_Clavicle.r
Execute following command in: vertex group specials: "mirror vertex groups (topology)"
See weights getting flipped instead of mirrored, as the command description suggests.

bug_report_001.blend

**System Information** Operating system: WIN 11 Graphics card: RTX 3090 **Blender Version** Broken: (example: 3.1.2, cc66d1020c3b, master) Worked: (newest version of Blender that worked as expected) **Short description of error** "mirror vertex groups (topology)" and "mirror vertex groups" command is always flipping weights instead of mirroring. See attached video. [2022-05-27 17-55-22.mkv](https://archive.blender.org/developer/F13115044/2022-05-27_17-55-22.mkv) **Expected behavior** When one bone is selected > mirror weight to the corresponding bone on the other side. When two corresponding bones are selected > flip weight of selected bones **Exact steps for others to reproduce the error** - Open attached blend file - Select armature and mesh - Go to weight paint mode - Select bone: CC_Base_Clavicle.r - Execute following command in: vertex group specials: "mirror vertex groups (topology)" - See weights getting flipped instead of mirrored, as the command description suggests. [bug_report_001.blend](https://archive.blender.org/developer/F13115047/bug_report_001.blend)

Silas Wittwer commented

2022-05-27 18:06:48 +02:00

Added subscriber: @OakenPixel

Pratik Borhade commented

2022-05-30 06:20:04 +02:00

Added subscriber: @PratikPB2123

Germano Cavalcante commented

2022-05-30 16:01:36 +02:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2022-05-30 16:01:36 +02:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Germano Cavalcante commented

2022-05-30 16:01:36 +02:00

This tool is confusing and the manual isn't helping much: https://docs.blender.org/manual/en/3.3/sculpt_paint/weight_paint/editing.html#bpy-ops-object-vertex-group-mirror

Expected behavior
When one bone is selected > mirror weight to the corresponding bone on the other side.
When two corresponding bones are selected > flip weight of selected bones

In my opinion the expected behavior should be just mirroring the vertex group without affecting another group (even with the .L or .R suffix).

This tool is confusing and the manual isn't helping much: https://docs.blender.org/manual/en/3.3/sculpt_paint/weight_paint/editing.html#bpy-ops-object-vertex-group-mirror > **Expected behavior** > When one bone is selected > mirror weight to the corresponding bone on the other side. > When two corresponding bones are selected > flip weight of selected bones In my opinion the expected behavior should be just mirroring the vertex group without affecting another group (even with the .L or .R suffix).

Philipp Oeser commented

2022-05-30 16:48:23 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2022-05-30 16:48:23 +02:00

Changed status from 'Needs Developer To Reproduce' to: 'Needs User Info'

Philipp Oeser commented

2022-05-30 16:48:23 +02:00

Topology Mirror is a strange beast.

Can we please try this with a symmetric mesh:

open the file
Mesh > Symmetrize
then use vertex group specials Mirror Vertex Groups
(note: while still in the Properties Editor, you can bring up the Adjust Last Operation panel with {key F9} to try out different options for Flip Names etc.

@OakenPixel: does this work with "regular" mirror on a real symmetric mesh for you?
If only Topology Mirror is borked then it might be a duplicate of #96191 (Topology Mirror mirrors wrong in weight painting mode) or blender/documentation#81698 (Topology Mirror usage)

`Topology Mirror` is a strange beast. Can we please try this with a symmetric mesh: - open the file - `Mesh` > `Symmetrize` - then use vertex group specials `Mirror Vertex Groups` - (note: while still in the Properties Editor, you can bring up the `Adjust Last Operation` panel with {key F9} to try out different options for `Flip Names` etc. @OakenPixel: does this work with "regular" mirror on a real symmetric mesh for you? If only Topology Mirror is borked then it might be a duplicate of #96191 (Topology Mirror mirrors wrong in weight painting mode) or blender/documentation#81698 (Topology Mirror usage)

Philipp Oeser commented

2022-06-07 12:14:40 +02:00

Changed status from 'Needs User Info' to: 'Archived'

Philipp Oeser closed this issue

2022-06-07 12:14:40 +02:00

Philipp Oeser commented

2022-06-07 12:14:40 +02:00

So, without further information there is no way to tell if this is issue is different from #96191 or blender/documentation#81698.
Without knowing, there is no point in keeping a separate report open for this.

Thx reporting, but will archive then.

So, without further information there is no way to tell if this is issue is different from #96191 or blender/documentation#81698. Without knowing, there is no point in keeping a separate report open for this. Thx reporting, but will archive then.

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mirror vertex groups command is always flipping weights #98450