CreateTerrainModifier

The CreateTerrainModifier method creates a Modify Terrain object in the 3D Window.

See: “Modify Terrain” section under the “Terrain Objects” chapter of the User Manual.

HRESULT CreateTerrainModifier(

[in, optional, defaultvalue(0)] VARIANT SafeArrayVertices,

[in, optional, defaultvalue(0)] ElevationBehaviorMode Mode,

[in, optional, defaultvalue(1)] long Flat,

[in, optional, defaultvalue(0)] double Feather,

[in, optional, defaultvalue(0)] long GroupID,

[in, optional, defaultvalue("")] BSTR Description,

[out, retval] ITerrainModifier5** pITerrainModifier5)

Parameters:

• SafeArrayVertices – An array that contains triplets of doubles. Each triplet is composed of an x-coordinate, a height, and a y-coordinate. The x-coordinate and y-coordinate define the modify terrain points, while the height value is applied to the respective point on the feather line. When the feather is set to zero, these points fall exactly above the respective X and Y coordinates. The COM interface represents the height in meters while the x- and y-coordinates are represented in MPT units. You can use the ITerrain interface to retrieve information about the MPT units. If you are working in a Lat-Long format, the Lat-Long values are given in decimal degrees. If the parameter is zero, the object manager creates an empty modified terrain object to which the client can later add vertices.
  See:  “Creating a Polyline Using a Safe Array of Vertices”.

• Mode – An enum determining the elevation behavior mode.

The ElevationBehaviorMode enum can use any of the following values:

• EB_REPLACE = 0
  Replaces the area defined by the polygon with the selected elevation value.

• EB_BELOW = 1
  Replaces all elevation values that are lower than the selected elevation value with the selected elevation value

• EB_ABOVE = 2
  Replaces all elevation values that are higher than the selected elevation value with the selected elevation value

• Flat – A Boolean that determines if the modified terrain creates a flat surface.

• Feather – The size, in meters, of the feather radius.

• GroupID – The Information Tree group in which the modify terrain is created. If it is set to zero, the object is created under the root. You can obtain the GroupID by one of the following methods:

• Create the group using IInformationTree5::CreateGroup.

• Find the group if you know the name of the group using IInformationTree5::FindItem.

• Traverse the Tree using IInformationTree5 methods such as GetNextItem(), until you come to the desired GroupID.

• Description – The name of the modify terrain as it appears in the Information Window. If an empty string is passed into this parameter, TerraExplorer assigns it a unique name.

• pITerrainModifier5 – An interface pointer to the newly created terrain modify object. This parameter must not be Null.

Return Values:

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