During a modification using either move, offset, taper, change radius or align, the operation often needs to enlarge freeform geometry. Often, the modified faces itself as well as the direct neighboring faces of the modified faces potentially need enlargement. Depending on the shape of the surface the enlargement distance might be limited or the surface might become self-intersecting or corrupt in the enlarged area. The Modify 3D commands try an automatic surface enlargement. However, this is limited to avoid enlarging the surfaces by more than their current size.
• Possible Solutions:
◦ Avoid generating freeform surfaces whose borders meet at a corner point nearly parallel or antiparallel. Generate more than one surface instead.
◦ Avoid generating freeform surface that are of strongly "tapered" shape.
◦ Use Untrim command with the replace geometry option if the automatic extension (twice original size) is not sufficient but can be safely extended.
◦ Use Untrim command to visualize how far the surface can be extended. If the extension is not the desired one, you need to modify the surface or add an additional surface using methods from the surfacing module like "extrude face" or "loft to part". (In the following example, loft to part was used.)
