Converts 3D solids and surfaces into NURBS surfaces.
Ribbon: Surface tab
Control
Vertices panel
Convert
to NURBSNot available on the ribbon
in the current workspace
Menu: Modify
Surface
Editing
Convert
to NURBSNot available in menus
in the current workspace
Toolbar: Surface
Editing
Converts solids and procedural surfaces to NURBS surfaces.

To convert meshes to NURBS surfaces, convert them to a solid or surface first with CONVTOSOLID or CONVTOSURFACE and then convert them to NURBS surfaces.