GetGroundHeight

The GetGroundHeight method retrieves the height of a given coordinate on the terrain using the given accuracy level.

HRESULT GetGroundHeight(

[in] double X,

[in] double Y,

[in] AccuracyLevel Level,

[out, retval] double* TerrainHeight)

Parameters:

• X – The West-East coordinate of the point of interest represented in MPT units. You can use the other ITerrain properties to retrieve information about the MPT units.

• Y – The North-South coordinate of the point of interest represented in MPT units. You can use the other ITerrain properties to retrieve information about the MPT units.

• Level – Defines the level of accuracy that you need for the retrieved elevation at the given coordinate. There are three levels possible from the least accurate (but fastest performance-wise) to the most accurate (but slowest performance-wise). The following are the three possible values:

• ACCURACY_BEST_FROM_MPT = 2
  This is the slowest method, but it retrieves the most accurate information. Using this flag can create a large performance hit especially if the terrain information is streamed via an Internet connection.

• ACCURACY_BEST_FROM_MEMORY = 1
  This flag tries to get the best information it has about the given coordinate elevation without reading it directly from the MPT (based on what TerraExplorer already has in memory). It is faster than the previous flag but does not guarantee the most accurate value.

• ACCURACY_ NORMAL = 0
  With this flag, the client gets the best performance. However, its returned information about the elevation at that point is the least accurate.

• TerrainHeight – When the method call returns, this parameter contains the height of the terrain at the given coordinate.

Return Values:

The return value obtained from the returned HRESULT can be one of the following:

Remarks:

The retrieved TerrainHeight is based on the information that was written in the MPT. This means that if the MPT was not built with correct height information, this method will also not work properly.