Non-Uniform Rational B-Splines (NURBS) provide a 3D modeling framework based on geometric primitives and drawn curves.
You can use NURBS in two ways:
Primitives are simple 3D objects created in the shape of common geometric forms such as cubes, spheres, cones, and so on. Primitives can be a great starting point for many 3D shapes. You can modify the attributes of NURBS primitives to modify their shape. You can also modify NURBS primitives by trimming away portions of their forms, beveling their edges, or by sculpting them into different shapes using sculpting tools.
To find options for constructing and modifying NURBS curves and surfaces: