To Create a NURBS Surface by Extruding

1. At the Command prompt, enter SURFACEMODELINGMODE and set the system variable to 1.
2. Click Modeling tab > Solid panel > Modeling drop-down > Extrude.
3. Select the objects or edge subobjects to extrude.
4. Specify the height.

   After the extrusion, the original objects are deleted or retained, depending on the setting of the DELOBJ system variable.