Hi Metin,

> This video shows the generation of the rounded 3D volume I mean from a 2D curve:

Unfortunately it's difficult to make this same kind of process happen with NURBS surfaces instead of polygons.

Polygons have the benefit of "arbitrary topology", you can stick a bunch of little ones together any way you want.

NURBS surfaces are not like that, a NURBS surface is made up of a regular grid of control points, with a specific row and column structure to it. You can't just add in a single point all by itself somewhere in the middle of a surface to make a protrusion, it has to be an entire row or column of points added in at one time.

The kind of technique that is used to make those puffy shapes in the video you linked to, really relies a lot on that "arbitrary topology" type structure, so it's hard to do the same thing with a NURBS surface.

- Michael