You can create a polygon mesh by converting a NURBS surface or assembled surface mesh. You can choose whether the generated polygon mesh follows the interpolated surface of the NURBS or the hull (that is, whether the vertices are created at the knot locations or at the control point locations).
To convert a NURBS surface to a polygon mesh
Choose Create 
Poly. Mesh NURBS to Mesh from the Model toolbar. A new polygon mesh object is created and the NURBS to Mesh property editor opens:
From Control Hull controls the placement of the polygon mesh's vertices.
When this option is off, vertices are located at the knot positions and along the interpolated NURBS surface.
When this option is on, vertices are placed at the positions of the surface's control points. If you apply geometry approximation to the resulting mesh to create a subdivision surface, it approximates the original NURBS surface.
Ignore Trims controls whether holes made by trim curves are included in the mesh. This option has no effect if From Control Hull is on.
The Step values specify the number of vertices per knot in each of the surface's U and V directions. The minimum is one vertex per knot. SrfCrv controls the accuracy along trims.
The parameters in the Stitch box control whether vertices are merged. If Active is on, then vertices that are closer than the specified Tolerance are merged.
This is useful for eliminating superimposed points as may occur at the poles of a surface sphere.
Whenever you generate a new object from other input objects, you can manage the inputs, for example, hide or delete them. See Managing Generator Inputs [Modeling and Deformation Basics].
