The terrain surfaces are part of the Geometric model of a dgn. To get all terrain surfaces with the terrain model from current dgn file, the below code snippet shows how this can be achieved.

Example

//Required SDK Libraries
using System.Collections.Generic;
using Bentley.DgnPlatformNET;
using Bentley.CifNET.GeometryModel.SDK;
using Bentley.CifNET.SDK;


internal void ListAllTerrainsFromDgn()
{
	//Get active dgn model
	Bentley.DgnPlatformNET.DgnModel activeModel = Bentley.MstnPlatformNET.Session.Instance.GetActiveDgnModel();
	//Get connection 
	Bentley.CifNET.SDK.ConsensusConnection con = new Bentley.CifNET.SDK.ConsensusConnection(activeModel);
	//Get geometric model
	Bentley.CifNET.GeometryModel.SDK.GeometricModel geomModel = con.GetActiveGeometricModel();
	if (geomModel == null) return;

	//Get all terrain surfaces from Geometric model
	IEnumerable<TerrainSurface> allTerrainSurfaces = geomModel.TerrainSurfaces;

	//Iterate over each terrain surface to get DTM
	foreach (TerrainSurface terrainSurface in allTerrainSurfaces)
	{
		//Get terrain model from terrain surface
		DTM dTM = terrainSurface.DTM;
	}
}

Copy to clipboard Get TerrainSurfaces from GeometricModel to get all terrains.