Page MenuHome

Subdivide operator affects hidden geometry?
Open, Needs Triage by DeveloperPublic


Blender Version
Broken: all or none

I'm not really sure this is even an issue, though it feels like it. As far as I understand it, mesh editing tools are not supposed to affect hidden geometry. But the Subdivide tool does. Consider this mesh:

If you hide the middle face...

...and then Subdivide the two remaining faces...

...Subdivide will create new edges cutting through the hidden face, also creating inconsistent selection (i.e. selected edges in face select mode). Shouldn't the operator check that that face is hidden and not create edges through it?



Event Timeline

Seems to be the same no matter if you hide it (or just leave the middle face unselected [but visible]).
It only wont create the connecting edges if there is another cut through the "middle" face.
Unsure what is intended here, needs further investigation...

Yes, when not hidden, it does make sense as the operator does subdivide opposing selected edges. That's why I'm specifically bringing up the hidden case, as it would seem it's a bit unclear if it should or shouldn't touch the hidden geo.
Upon further exploration it would seem that tools don't have an agreement on this:

  • Loop cuts do end at hidden faces, but knife cuts through them; bisect doesn't cut hidden.
  • Vertex slide doesn't slide along hidden edges, but edge slide does.
  • Offset edge slide adds an edge on hidden face.
  • Inset doesn't treat edges around hidden faces as boundary (unlike Loop Cut).
  • Bevel cuts into hidden faces (and creates hidden faces with unhidden edges).