Triangular irregular network generation and topographical modeling

Abstract

A triangular irregular network (TIN) is created by linking triplets of nodes to form non-overlapped triangles and is suitable for modeling natural complicated topography. This paper presents an efficient network generation method which decomposes a domain into small cells (rectangular grids) to avoid exhaustive searching of points or lines (i.e., avoid any global process), and minimizes process steps by using a shape parameter to avoid triangles with extreme angles. A shape correction method is then imposed to optimize the network. Using different size of cells and shape parameter will result in the effect on the final mesh quality. CPU time required, and errors induced are studied. This methodology can also handle constrained problems with prespecified segments, holes, and boundaries in a model; furthermore, the functions of user-defined cell size and shape parameter can result in different outcomes and provide alternatives for an user to process a problem.