If any questions about this funny method of subdivision inside Nurbs don't hesitate!
Thx Max Smirnov for these magic tools!

Advantage is the very few tools to learn/use! :)

- Extrude face(s) (not on the extremities)
- Scale with Points enabled
- Split on a single Edge or a face(s)... don't need to recall it, just Right Click
- Bridge only between 2 faces : careful of overlapings
( useful for replace the Extrude at the "extremities" : just Copy / Move the face then Bridge )

Show Points from the beginning, and never accept the SubDive before the final result wanted... :)

Here just a tranparent Texture of the Engine Render...