If
you want to keep the region you trimmed away, select Keep.
To discard the region you trimmed away, select Discard.
The default is Keep.
Shrink Surface
Causes
the underlying surface to shrink to just cover the retained regions.
This permanently changes the surface geometry and cannot be restored
by untrimming, but Undo will still work.
Fitting Tolerance
Specifies
how precisely the Trim Tool uses the shape of
the curve-on-surface when it trims the surface. The default value
works well in most cases, but you can use a smaller value to increase precision.
Keep Original
The
original surface is retained after the trim is performed. If the
surface and the curve-on-surface were created with construction
history turned on, you must keep the original geometry.
