A terrain model is a set of triangles mathematically computed from point data collected from the surface being modeled. They are typically used to model highly irregular surfaces, like the surface of the earth. A terrain model is created from 3D features such as points, breaklines, and contours. Terrain models are also referred to as digital terrain models (DTMs), triangulated irregular networks (TINs), or triangulated surfaces.

The terrain models are stored as 3D file, but we can refer them inside 2D design file.

OpenRoads Designer provides API's for creating and editing terrains, terrain analysis. Such as creating terrains from files, elements, graphical filters, and other additional methods. Edit operations such as set terrain as active, add/remove features, change feature type, edit model, Boundary editing - add/remove boundary, and transformation - translation/rotation/scaling elements. Terrain analysis provides features for point analysis, calculating terrain areas, create/cut/analyze terrain volume, create/cut/analyze ponds, exporting terrains etc.

This image shows the terrain boundary with triangles.