Algorithms of Producing Tetrahedral Network from Three Dimensional Dispersed Data

In the fields of resources, environment and engineering exploration, tetrahedral network created up from the three dimensional dispersed data is of great significance for making three dimension spatial analysis to obtain the distribution of unknown three dimensional spatial objects. Based on the analysis of the triangulation irregular network algorithms, the authors put forward three ideas and steps of building tetrahedral network. (1) Triangulation growth: The first tetrahedron is first generated in a data field. Then a new tetrahedron is spread out from one surface of the tetrahedron. This continues until all discrete points are connected to a network. (2) Incremental insertion: The un processed data are inserted in the existing tetrahedral network, once a point. Then the local optimization procedure of the network is realized. (3) Divided conquer: First, the data are ordered. Then the collections of data points are recursively divided until each collection only includes four points to form a tetrahedron. Finally, every tetrahedral network is merged from lower level to upper level until the last tetrahedral network is produced.