This .NET class wraps the AcGeCurveBoundary ObjectARX class. 

CurveBoundary is a class that is used to communicate boundary geometry that exists on a bounded surface. In the most general case, each instance of this class consists of four arrays: an array of 3D curve or 3D position pointers, an array of parameter space curve pointers, and two arrays of Booleans. One Boolean array indicates the logical orientation for each 3D curve, and the other indicates the logical orientation for each parameter space curve. 

Collectively, these four arrays represent an array of oriented 3D space curves or 3D positions, and an array of oriented parameter space curves. There is a one-to-one correspondence among all arrays that are present. However, certain elements of a given data array could be null, or irrelevant. 

For example, the following four tuple is a legal element of this class: (curve3d*, NULL, False, True). The first element of the tuple is the 3D space curve. There is no parameter space curve associated with the 3D space curve. The logical direction of the 3D space curve is opposite to that of the parametric direction of the curve. Since there is no parameter space curve, the last element of the tuple is not applicable (if the parameter space curve was present, then this element would be the logical direction of that curve). 

In general, the information obtained through an instance of this class, and the interpretation of that information, depends on the context in which it is used. An example of a use of CurveBoundary is to extract the curve boundary information associated with an instance of ExternalBoundedSurface.

Autodesk.AutoCAD.Geometry.CurveBoundary

Public sealed Class CurveBoundary
Inherits DisposableWrapper
Inherits ICloneable

public sealed class CurveBoundary : DisposableWrapper, ICloneable;