In this example, we'll be looking at how to retrieve information about NURBS surfaces, starting with the number of control vertices (CVs) they contain.
However, the number of CVs in a NURBS object isn't quite as straightforward as the number of vertices in a polygonal object. Although polygonal objects are relatively simple, with their shape determined directly by the position of the vertices, the curvature at any given point of a NURBS object is influenced by multiple points. The exact number of points that influence a given area depends on the degree of the surface.
To see how this works, we'll create a script that will determine the total number of CVs in each direction (U and V) of a NURBS surface, and we'll look at how to select a particular CV.