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is it possible in blender v2.70 or with a python function deselect neighbours faces, so that they are alone ?

i'll upload a picture to understand what I mean.enter image description here

I hope it's doable.

DevilSam
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1 Answers1

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Using bmesh

Yes it is do-able.

  • Add all selected faces to one set
  • Remove the active face from set

  • Find all neighbouring faces

    • Going by screenshot, this is any face that has an edge in the edge loop of each of its vertices is deselected.

  • Remove them from the selection

  • Repeat with next selected face until exhausted.

enter image description here Result of running on this grid with all selected

Test script, run in edit mode. Have a face as the active selection.

import bpy
import bmesh

context = bpy.context
ob = context.edit_object
me = ob.data
bm = bmesh.from_edit_mesh(me)

selfaces = set(f for f in bm.faces if f.select)

f = bm.select_history.active
selfaces.remove(f)
while True:

    # find all "neighbours" of f
    desel = set(f for v in f.verts for el in v.link_edges for f in el.link_faces)
    for f in selfaces.intersection(desel):
        f.select = False
    selfaces -= desel
    if not selfaces:
        break
    f = selfaces.pop()
bmesh.update_edit_mesh(me)

Recommend checking out bmesh via the py console. With a mesh in edit mode

>>> import bmesh
>>> bm = bmesh.from_edit_mesh(C.object.data)
>>> bm
<BMesh(0x7f3308fde308), totvert=100, totedge=261, totface=162, totloop=486>
batFINGER
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  • batFINGER you are a GOD ('o') – DevilSam Jan 15 '19 at 09:45
  • the script from https://blender.stackexchange.com/questions/128870/set-random-active-face-in-python-without-toggle-mode i get "AttributeError: object has no attribute 'ensure_lookup_table'" in Blender v2.70, but if I put this in blender v2.79 it works, but than when i start the (Deselect Neighbours Faces script) I get the "Report Error KeyError: None" – DevilSam Jan 16 '19 at 11:22
  • Why blender 2.70? On the keyerror, most likely at selfaces.remove(f) How are you choosing f? bm.faces.active can be None, as can select history active. Trying to remove None from a list that doesn't contain it will throw that keyerror. This is why I implore you to test things out in the py console. For some random selected face f = selfaces.pop(randint(0, len(selfaces) - 1) will randomly remove one selected face (still selected) from list. Using this won't need that remove statement. Why the need to loop this? – batFINGER Jan 16 '19 at 12:03
  • i use blender v2.70 because the functions that work under 2.70 are also the new versions of compatible. here a video: https://streamable.com/j9ojn – DevilSam Jan 16 '19 at 12:57