Spin Edge for Rhino SubD Tools

According to the Pushing Points Topology Workbook, Spin Edge or Rotate Edge is an expected tool for polygon/subd modelling. So, I decided to roll my own.


Current Limitations:

  • Nothing to support triangles or ngons yet
  • Some face cases that don’t appear to work. This is probably due to the simplistic nature of the script and logic I’ve employed, which is rather heavy handed This can be seen in the gif, might be something about topological vertices
  • Not supported for meshes, just subds so far
  • Any creasing information will be lost as I convert from subd > mesh > subd


  • Where vertices in a mesh lie in a straightline, during the subd conversion these points are removed? See below. On the left, converted to subd after moving the inline vert out a little bit. Is this by design?

! _-RunPythonScript "<full path to your script including extension>"
(Path example: "C:\Users\<username>\Documents\Myscripts\TestScript.py" )

Spin Edge.py (7.0 KB)

@theoutside is this a tool that has ever been in development, or suggested by devs/users?


we have a swap edge for mesh tools but they do not work on subd-

would be a good add to the toolset.


Thanks Kyle. Just for my own satisfaction, it would be interesting to hear if my logic worked out! Also regarding the bug of the mesh having edges that line up, when converted to subD these points evaporate.

Pretty much happy to just contribute the code I’ve made to the community to use. Not sure who deals with SubD though.

I’d have to defer to the math and programming folks…I’m but a humble art school grad.

Nice, I’ve just found this topic since I was confused by the naming of the command.

Looks like this is available as a native command now…


yep- SubDSpinEdge is the command

Cool! It was a fun scripting exercise for me and nothing more :smiling_face: would be cool to see what the pro solution was! I think it was @pierrec

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