The Esri TinEdge component.
The TinEdge object is one of the three basic elements of a TIN: nodes, edges, and triangles. Edges are comprised of two nodes, a FromNode and a ToNode. Edges are oriented in clockwise order and are used to form triangles.
TinEdges may be hard, soft, or regular. Hard and soft edges are enforced in the triangulation. When a TIN is used as a surface model, these usually represent breaklines. Regular edges are simply a consequence of triangulation and dont' have special meaning. The esriTinEdgeType enumeration describes edge type.
Edges have both dual and single representations in a TIN. A given edge has an index, a FromNode and a ToNode, a LeftTriangle and a RightTriangle. If you use ITinEdge.GetNeighbor it returns the corresponding edge in the adjacent triangle. That edge has a different index and its from nodes, to nodes, left and right triangles are opposite of the original edge. In this sense there are two edges between each triangle; the dual representation. On the other hand, a number of properties and functions treat both edges logically as one. Edge type and tag value are shared. These properties will always be the same for both edges. A change in property of one edge is automatically reflected in the other. Selection functionality (see ITinSelection ) works the same way. Selection of one edge automatically results in the selection of its neighbor.
Extended Error Information
Use the ISupportErrorInfo method InterfaceSupportsErrorInfo to determine if the object supports extended error information. If the object supports extended error info, VC++ developers should use the OLE/COM IErrorInfo interface to access the ErrorInfo object. Visual Basic developers should use the global error object Err to retrieve this extended error information.
|ISupportErrorInfo||Indicates whether a specific interface can return Automation error objects.|
|ITinEdge||Provides access to members that control TIN edges.|
|ITinElement||Provides access to members to control TIN elements.|
|ITinFeatureSeed||Provides access to control TIN elements' properties.|