The ESRI TinDataElementFilter component.
The TinDataElementFilter is used to filter nodes, edges, and triangles based on whether they are within the interpolation zone, or data area, of the TIN.
TIN elements (nodes, edges, triangles) can exist inside or outside the TIN's data area. When TINs are built from points or breaklines the data area is a convex hull that includes all user entered data. The only elements that are 'outside' are the four supernodes and their incident edges and triangles. If clip or erase polygons are added to the TIN they further modify what is considered to be 'inside'. This occurs through triangle masking. See TinTriangle for more information on masking and data area delineation.
The TinDataElementFilter is typically used with a TIN element enumerator (e.g. TinNodeEnumerator) to return either those elements that are inside the TIN's data area, or all elements. This is the most basic TIN element filter. It implements ITinFilter. Use this filter when you're only concerned about inside vs. outside. Other TIN filters implement interfaces which inherit from ITinFilter and therefore can filter on this plus additional properties.
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.