NURBS curves and surfaces are approximated by straight segments to speed up processing and display. You can control the accuracy using geometry approximation.
To apply and edit Geometry Approximation properties, see Applying and Editing Geometry Approximation [Scene Elements].
Geometry Approximation is a multi-purpose property, and not all of the options apply to NURBS curves and surfaces. The following options are the ones that do apply to NURBS:
Hardware Display controls how NURBS curves and surfaces are displayed in the OpenGL views.
Surface controls how NURBS surfaces are rendered.
Surface Trim controls how the trimmed edges of NURBS surfaces are rendered.
Displacement controls how displacement maps are rendered, if you are using them. It affects both NURBS surfaces and polygon meshes.
For a complete description of all options, see Geometry Approximation Property Editor [Properties Reference].
