With Skin Modifier, we can "weight" a vertex (in Edit Mode) so that the resulting Skin mesh is bigger or smaller - similar to Curve objects which has "Scale Feather" adjustable.

Manually, we can hit Tab, go to Edit Mode, select Vertices, then CtrlA and drag.

However, I would like to be able to do this using Python. Does anyone know anything about it?


Reading and writing these values from Python must happen in Object mode. I added a plane and deleted one vertex, added the skin modifier and decreased the radius of one vertex.

>>> obj = bpy.data.objects['Plane']
>>> for v in obj.data.skin_vertices[0].data:
...     print(v.radius[:])
(0.25, 0.25)
(0.25, 0.25)
(0.08836718648672104, 0.08836718648672104)

Each element in skin_vertices[0].data has radius, use_loose, use_root to read and write. Radii can be any two element iterable (tuple, list).

import bpy

obj = bpy.data.objects['Plane']
for v in obj.data.skin_vertices[0].data:
    v.radius = 0.2, 1.2

I just realized that CtrlA lets you constrain the effect on radius per axis with ShiftX,Y.

| improve this answer | |
  • 1
    $\begingroup$ Thanks so much for this answer @Zeffii! Right on solution. I was also surprised that we can constraint the effect either with X or Y axis. Only obvious when checking the radius value using Python, and it gives 2 values. Very interesting. I found this blog post that kind of talks a bit about the radius weight for skin vertices: michelanders.blogspot.com.au/p/… I will soon post this in my blog. $\endgroup$ – Blender Sushi Guy Jul 3 '13 at 1:21
  • 2
    $\begingroup$ @BlenderSushiGuy to let others know that this answer satisfies your question please log in with your other account and accept it. I recommend that you stop using two usernames, it's extra work in the long run. $\endgroup$ – zeffii Jul 3 '13 at 5:23
  • $\begingroup$ I first thought skin_vertices will contain data for each skin modifier (in case there are more than one), but it always has one element corresponding to first-added skin modifier! BTW great finding! $\endgroup$ – mg007 Aug 2 '13 at 18:36

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