A TIN is a digital representation of the surface of the Earth that is
composed of a set of nonoverlapping triangles. The Delaunay
triangulation approach is used to create a TIN from DTM mass
points. In order to create a raster DEM output, the DTM mass points
are used as reference points to interpolate an elevation value to
create a raster grid DEM. The ESRI 3D Shape file and ASCII file
output options simply detail the DTM mass points.