Indicates if the passed value is equal to the TIN's void value.
[C++] HRESULT IsVoidZ( double Value, VARIANT_BOOL* pbIsVoid );
ParametersValue [in] Value is a parameter of type double pbIsVoid [out, retval] pbIsVoid is a parameter of type VARIANT_BOOL
Returns TRUE or FALSE depending on whether the specified Z is considered NODATA. Mathmatical operations cannot be performed on NODATA.
Some functions, such as ISurface.GetElevation, return a floating point number representing some characteristic of the surface for a given location. If the location does not fall within the interpolation zone some value representing NODATA must be returned. IsVoidZ can be used to evaluate if the result is NODATA.
The super nodes of a TIN have a Z value equal to NODATA. A super node is one of four nodes added by the software when a TIN is initially created (ITinEdit.InitNew). They reside far outside the declared data extent and are used to define an initial triangulation before user data gets added. Triangles incident to these nodes are always flagged as being outside the TIN's interpolation zone.