The extension surface can be merged as part of the original surface, or appended as a second surface adjacent to the original surface.
The following prompts are displayed.
Specify Extension Distance
Specifies the extension length.
Expression
Enter a formula or equation to specify the length of the surface extension. See Constrain a Design with Formulas and Equations.
Modes
Extend. Extrudes the surface in a way that tries to mimic and continue the shape of the surface.
Stretch. Extrudes the surface without trying to mimic and continue the shape of the surface.
Creation Type
Merge. Extends the surface the specified distance without creating a new surface. If the originating surface is a NURBS surface, the new extension surface will also be a NURBS surface.
Append. Creates a new extension surface that is adjacent to the original surface.