Say, I lay down a Surface NURB Circle in Blender. It has 4 control points, and it is circular. Now, if I Subdivide it to add more control points, it starts to become a square. The more I subdivide the more square it becomes:
What I'd like to know is if there is a way to subdivide the original circle and have Blender add new control points such that the original circular shape is preserved. Same goes for any Surface NURB. I'd like to be able to add new control points without destroying the shape of the curve.