Generation of a virtual terrain

A computer software package, TERAN, has been written for the generation of a virtual terrain. Originally intended for use in defining the topology in complex, individual-oriented ecosystem models, TERAN is sufficiently versatile that it may be used to create elevation grids for a wide variety of applications. Moreover, it is structured so that the existing features of the software can be easily modified, and new features added without difficulty. First, the user to define the dimensions and resolution of a rectangular coordinate grid. The user is then able to choose from a variety of models for the overall surface configuration, surface roughness, and up to 100 major surface disturbances. Parameter values are then input for each of these, and the resulting terrain definition can be saved to file for subsequent retrieval and modification. After terrain definition is complete, the surface elevation is calculated for every point in the coordinate grid, taking into account the influence of each topographical feature by invoking the appropriate mathematical model and then summing the elevation increments. The completed rectangular matrix of elevation values is exported in ASCII format for use with other applications (e.g. modeling packages, GIS, graphical display).