Advanced Features

Under Advanced Features there are five items. They are mainly designed for performing some advanced geometric algorithms and design activities. These five items are Degree Elevation, Knot Insertion, Knot Splitting, Surface Subdivision, and Cross Section Design. Except for Cross Section Design, each item can be performed on U or on V.

  1. Degree Elevation performs degree elevation in u- or v- direction. See Degree Elevation for the details.
  2. Knot Insertion performs knot insertion in u- or v- direction. See Knot Insertion for the details.
  3. Knot Splitting performs knot splitting in u- or v- direction. To perform a knot splitting, you should move the little triangle that indicating the value of a knot in the u- or v- direction to a multiple knot, and select Knot Splitting, followed by the direction. The indicated multiple knot will be split into two. One of them is a simple knot whose position will be very close to the selected knot. If the multiplicity of the original multiple knot is k, the second knot will have multiplicity k-1.
  4. Surface Subdivision performs surface subdivision in u- or v- direction. You can select Disable/Enable Maintaining C1 to disable or enable maintaining C1-continuity along the boundary curves. See Degree Elevation for the details.
  5. Cross Section Design activates the cross section design subsystem. This will bring up the curve subsystem for you to design ruled surfaces, surfaces of revolution, swung surfaces, swept surfaces, and skinned surfaces.