Unexpected merging of vertex groups with different names
Closed, ResolvedPublic

Description

System Information
Win 7 64 bit

Blender Version
Broken: 2.79

Short description of error
Mesh called Array is using array modifier with start cap option, all vertices of it belong to "Mask" vgroup. Some vertices of Start Cap mesh belong to "Bevel" vgroup.

When I choose "Bevel" group in Bevel modifier, vertices that are not in this group somehow merging with "Mask" group of Array mesh.

Exact steps for others to reproduce the error
Open file, choose "Bevel" vgroup in Bevel modifier -> see how another mesh is masking

PS. Workaround is to create another empty vgroup in the Start cap mesh and place it before "Bevel" group

Serge Lyatin (SergeL) renamed this task from Unexpected merging of vertex groups to Unexpected merging of vertex groups with different names.
ronan ducluzeau (zeauro) triaged this task as Confirmed priority.Oct 31 2017, 11:19 AM

It looks like array modifier is not using name but index of vertex group.

It is interesting to be able to apply an effect depending of vertex group on cap and array after array modifier.
But yes ! Vertex groups with different names should not be merged.
Or, at least user should be warned.

I have added a patch, but I don't know if I did it correctly.
If you can see it: Is it okay to fix it that way?