QueryPointVisibility

This method executes a visibility query (either StartShadowVisibilityQuery or StartViewshedVisibilityQuery) based on the parameters set by the last StartXXVisibilityQuery call. Multiple calls to QueryPointVisibility can be made. When the queries are finished, EndVisibilityQuery should be called to free system resources.

Parameters

QueryPosition

An IPosition80representing the position for which the query is being performed.

Return Value

pVal

The value returned by the visibility query:

·          1 – visible

·          0 – not visible

·          -1 – QueryPosition is outside of the region defined for the analysis. This area is defined in the StartShadowVisibilityQuery and StartViewshedVisibilityQuery.

·          -2 – Error

Exceptions

HRESULT can return any of the values listed in the HRESULT Return Values list, as well as the following value:

§   TE_E_OUT_OF_RANGE - Point is not in the shadow/viewshed area