N-Sided
Patch Face 
Insert
Shapes (Standard)
Use this command to create
a face by patching across 3 or more profiles. The profiles can be wireframe
geometry, sketches, or face edges.
As boundary curves are selected,
graphic symbols are echoed to show curve
chain discontinuities. Red
triangles are used for curve segment joints that are not tangent continuous
(effectively, the end points of the n-patch) and orange squares for all
disjointed curve segment end points. This
will alert you to suspect curve geometry that would cause the command
to fail.
Required inputs include the profiles to define the patch. The optional inputs include tangency at boundaries, refitting and the ability to provide a unique name for the patch if desired. Refer to the Optional Inputs below.
Edges
Select the profile boundaries for the patch. You can use wireframe geometry, sketches or face edges.
Tangent at boundary
Check this box to force boundary edges to be tangent continuous with mating faces.
Refit
Use this option to refit curves to help prevent abnormal characteristics such as creases to occur. The refitting is performed by approximating the curve with a new curve to a given deviation tolerance (see below). This option may be beneficial under the following conditions:
When rational and non-rational curves get matched in the profiles.
When the original curves contain too many control points (some imported curves).
When curve degree is too high (some imported curves).
Select from the following options:
No - Do not refit curves.
Tangent - The refitted curve is tangent continuous throughout its length.
Curvature - The refitted curve is curvature and tangent continuous.
Direct -An alternate more direct approach to refitting is applied. This can help even out parameter spaces for compound boundary curves to avoid "pinching."
Tolerance
If the Tangent or Curvature refit option (see above) is selected, specify the deviation tolerance for refitting curves.
