Create NURBS surfaces when you need a freeform way to sculpt a surface shape.
Create NURBS surfaces by enabling NURBS creation and using many of the same commands used to create procedural surfaces. You can also convert existing procedural surfaces into NURBS surfaces.
NURBS surfaces are based on Bezier curves or splines. Therefore, settings such as degree, fit points, control vertices, weights, and knot parameterization are important in defining a NURBS surface or curve. Splines are optimized to create NURBS surfaces, allowing you to control many of these options. The illustration below shows the control vertices that are displayed when you select a NURBS surface or spline.
Two Methods for Creating NURBS Surfaces
There are two ways to create NURBS surfaces:
- SURFACEMODELINGMODE system variable. Use any of the surface creation commands while this system variable is set to 1.
- CONVTONURBS command. Convert any existing procedural surfaces to NURBS surfaces with this command.
It is important to plan ahead with NURBS modeling, since NURBS surfaces cannot be converted back into procedural surfaces.