Selecting per index: Inconsistend Indices?

Coding Python Support
1

Hi,
I started my first custom object creation addon, and already have come quite far.
One problem Is that now get inconsistent indexes, which leads to errors, as I select vertices / edges per indexes for
some manipulation.

I thought that only operations, which obviously change the mesh structure (subD, extrude, delete etc.) would change the index structure. Can others (selecting, moving, scaling) can have an influence as well?

One special case is the deletion of a face, which actually shouldn’t delete any vertices or edges (to create a hole on a surface). Can this still effect vertice/edge indices?

Another thing is some inconsistend indices after extrusion of multiple selected faces. Is there a way to get consistend indices (e.g. a “re-index” command or else)?

As always thank you in advance.

2

Transform operations shouldn’t change vertex indices, and face-only deletions shouldn’t either I guess. But indices are not really reliable, so you shouldn’t rely on them. With Bmesh module, it’s possible to change indices manually:

http://www.blender.org/documentation/blender_python_api_2_70_release/bmesh.types.html#bmesh.types.BMVert.index

You can also sort mesh elements in the standard API:
bpy.ops.mesh.sort_elements(type=‘VIEW_ZAXIS’, elements=set(), reverse=False, seed=0)

3

Thank you very much CoDEmanX!
I will take a closer look int the methods you pointed out.