A Modified Dem for Representing Overhanging Terrain

We propose a modified Digital Elevation Model (DEM) that stores additional data to adequately represent overhanging terrain. The DEM contains one additional line in the header information that describes the encoding of the data for any overhanging structures, arches, or caves. This additional data is then appended to the end of the normal DEM file. We describe a procedural approach to render arches using this modified DEM. This procedure can thereby generate terrain from ground truth data as opposed to many current methods. The new DEM is backward compatible except for the one additional line in the header; it is also space efficient, needing minimal data necessary for representing the overhanging terrain, thus keeping the file size at O(n
²
).