This class represents the boundary geometry (face loops) on a bounded surface.

Each face loop consists of four arrays: 

• 3D curve or position pointers
• 2D parameter space curve pointers
• 3D orientations
• 2D orientations

There is a one-to-one correspondence between elements in the arrays, although certain elements of a given array could be NULL, or meaningless. 

Loop degeneracies are represented as follows: 

• The entire loop degenerates to a single model space point, which is represented by the tuple (numElements = 1, position3d, curve2d). The curve2d may be NULL. The edge sense, and the curve2d sense are irrelevant. isDegenerate() method allows the determination of this condition on a loop.
• A loop consisting of one or more model space degeneracies is represented as the general case with those edges that are degenerate represented by position3d. This implies that in the general case, model space geometry of a curve boundary may consist of curve3d and/or position3d pointers. Consequently, this geometry is obtained by the user as entity3d pointers. The degeneracy of a constituent edge can be detected by the type of the model space geometry.

This class also supports the ownership of its geometry. Being the owner of its geometry would cause it to remove the geometry on destruction of an instance of the class. 

Corresponding C++ library: TD_Ge 

Working with Curve Boundaries