Extrude SubD in Normal Direction without tapering

Hi All I am exploring the extrude SubD in Rhino with a Cylinder and the purpose is to extrude the faces together around the cylinder in their individual Normal Directions just as T spline or Clayoo would.

I use the ExtrudeSubD which kind of works but the only problem is the faces will taper involutarily during the extrusion. I am already using the UVN and Normal option (please see attached file and screen cap).

Would anyone know how to make the extrusions straight without tapering along the way?

Thank you so much!


ExtrudSubD.3dm (4.7 MB)

Hi @rhinospaced,

Crease the edge ring before extruding:


Hi Jeremy

Thanks for your tip, it works indeed, however if i were to extrude them again I would need to crease them once again! I wish it could be like Clayoo or TSpline where we could just extrude straight (or tapered) based on its local normals !
And would you know how to select a ring of edges quickly? (I know Loop is double clicking the next edge)
Thanks and regards!

Lots of ways to select an edge ring, including:

  1. Select an edge with ctrl shift click, the select the next edge in the ring with ctrl alt shift double click.
  2. Turn on edge filter and select an edge with click, then the next edge in the ring with alt shift double click.
  3. Turn on edge filter and area select across the ring (easier with bottom right to top left option.
  4. Use the edge ring selection command
    a.k.a. SelEdgeRing.

Incidentally, the edge ring selection command will select all your new vertical edges if applied to the bottom ring of your model (but it doesn’t grab the horizontal ones). Quick way to crease all those new faces before the next extrusion.


Got that, thanks.

RH-62032 ExtrudeSubD: allow ‘Crease=Yes/No’


Shouldn’t that option be named more unambiguously?
Something like: ExtrudeSubD: ‘normal direction=Edge/Average’

Hi @norbert_geelen

Which option are you referring to?

  1. There is the existing ‘Direction = Free N’ (normal),
  2. There is @Pascal’s new option ‘Crease = Yes No’ which is (I’m assuming) about whether the new edges will be creased or not. To which I’d consider adding a third: ‘Repeat’ (the existing mix),
  3. There is also the possibility of an option to override the control of the taper of the new branch which is currently according to the crease state of the existing edges. Possibly by an option like ‘Sides = Parallel Radial EdgeLed’ (the last to retain finer control - you might want different u and v outcomes). I think this may be what you are referring to? Personally, I would prefer to keep direction and taper as separate options.


Thanks Jeremy that was great help, looking forward to the next update in SuBD indeed!

Hi Pascal

Thanks for putting it into the agenda. There is another suggestion if I may is that in some programs like 3D MAX (and maybe Tspline I can’t remember), when we have selected a face, and wanted to select its edges there is a button to toggle between whether to highlight the selected face’s edges, vertices or polygon.
Would this be a worthwhile update as well?

Please excuse my ignorance if this is already incorporated or if there were other smarted ways that already exists.

Thanks and regards

Hi Yutaka -

The SubDFaceEdgeVertexToggle command lets you do that.

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