easy way to iterate over the loose parts of a mesh?

Coding Python Support
1

Hi everyone,

I’ve been trying to improve a little script of mine and add some features to it,
one of which would require iterating over all the loose parts of a mesh (without splitting it of course).

I can’t seem to find any built in property or method that returns the list of loose mesh islands.
Did I miss something or is will I really have to find some hacky way around this?

2

This’ll get you started:

http://www.blender.org/documentation/blender_python_api_2_66a_release/bpy.ops.mesh.html?highlight=separate#bpy.ops.mesh.separate

You want the “Loose” option. As you notice, this actually splits the object into several objects. But once you’re done modifying it, you can rejoin them using:

http://www.blender.org/documentation/blender_python_api_2_66a_release/bpy.ops.object.html?highlight=object.join#bpy.ops.object.join

If you really can’t split the object (e.g. if you need consistent vertex indices that might get mixed up during the split) it’s still not too hard.
Pseudo-code:


Switch to edit mode
Add all vertices to "unprocessed" list.
While (unprocessed verts remain):
Deselect all vertices
Select any one unprocessed vert
Call built-in API function [select_linked](http://www.blender.org/documentation/blender_python_api_2_66a_release/bpy.ops.curve.html?highlight=select_linked#bpy.ops.curve.select_linked) 
Remove all selected verts from unprocessed list
Do whatever you need to do with this loose part
3

Thanks supergra!
I like your idea. It preferable to splitting and joining back the mesh I think (sounds like it could mess things up regardless of the vert indices)

Cheers