More control for SubD to Nurbs faces?

I am trying to use the Subd to Nurbs function to create a model with ‘Packed’ faces.

My problem is that in some areas it creates quite big areas that are merged together which create some quite extreme curvatures. Some CAD programs can’t read those properly.

Other areas are perfectly fine.

I would like to have some control over which areas are getting merged when packing the faces. Is there a way to do this?

I tried to have a look at the face maps/packs which seem to represent how the Nurbs faces are getting merged. But I am unable to edit/define those face maps.
Is there a way to do this?

My current workflow is this:

  1. Create a quad mesh in Blender
  2. Use toSubD function in Rhino to create a smooth surface
  3. Use toNurbs function in Rhino with packed faces enabled

@pierrec - do you have any ideas here? As far as I know there is no user control, correct?


@Mar2 The short answer is that there is no user control for SubD ToNURBS. I’ve written some more details in this post before: Converting SubD (4k faces) to Nurbs and Maintaining Topological Symmetry - #7 by pierrec.

It seems there is a bit of a way I can control the face packs though it seems.
I tried to use the Add Crease function which changes the way the faces are grouped. (I can then remove the crease again but the face group stays the same)