TIN File Format Specification
This chapter describes a triangulated surface model file format of TerraModeler. The file format is free for anyone to read and write. It is recommended to use extension .tin for TerraModeler TIN files but this is not mandatory.
The file format is meant for storing triangulated terrain models. The file format can store both xyz points and triangles which connect the points.
The triangle records are optional in the file. They may be left out of the file to save disc space if no manual editing of the surface has been done. The point records store all the relevant information from which the triangulation can be calculated as needed. However, if a user modifies the surface model (for example, assign additional breakline connections between points, mark areas as excluded, etc.), the triangle information must be stored and the triangle records contain the up-to-date edges of the surface.
