Each NURBS primitive has an associated set of attributes. Some attributes are common to all NURBS primitives, and others are specific to just one or two. By changing these attributes, you can alter a surface’s appearance.
You change all NURBS primitive attributes in the same way. In this section, we’ll show you how to change the radius attribute of a NURBS primitive. You can follow the same steps to change other object attributes. The following section defines many of the NURBS primitives’ attributes.