A terrain model is a set of three-dimensional triangles mathematically computed from point data collected on the surface being modeled. Models are used to define highly irregular surfaces, particularly the surface of the earth, but can be generated for proposed surfaces, subsurface geotechnical layers, etcetera. Terrain models are also referred to as digital terrain models (DTMs), triangulated irregular networks (TINs), or triangulated surfaces.

The MicroStation Terrain Model tools support importing and labeling terrain contours and spots on terrain models. You can import a terrain model into a DGN to use its data. Terrain models imported from the LandXML file format are supported within MicroStation. However, any manipulation or importing from Civil products must be done within Bentley Civil.

Bentley Civil provides a robust set of tools to create, edit, analyze, and work with terrain models.

Terrain Model as a MicroStation Element

A terrain model is recognized as a MicroStation element type as of MicroStation V8i (SELECTseries 3). When you select a terrain model, the Element Selection tool Element Type tab indicates that it is a Terrain element type.

Models Using SELECTseries 2 and SELECTseries 3

If a DGN file with a terrain model is created in MicroStation V8i (SELECTseries 3) and the DGN file is then opened in MicroStation V8i (SELECTseries 2), the terrain model will not be visible. The Terrain element type was not recognized prior to MicroStation V8i (SELECTseries 3). Although the terrain model is not visible, there is no data loss and the DGN file can be reopened in MicroStation V8i (SELECTseries 3), where the terrain model will again be visible.

If a terrain model created in MicroStation V8i (SELECTseries 3) needs to be used in MicroStation V8i (SELECTseries 2), then the terrain model can be dropped. When it is dropped the terrain model is removed and replaced by graphical elements, such as lines, shapes, and text.