Raster algorithms for generating Delaunay tetrahedral tessellations

Recently, many application domains need 3-D GIS. Delaunay tetrahedral tessellation (DTT) has been concerned as one kind of simplest data structure for 3-D GIS modeling due to its many advantages. But since 3-D geometry is poorly understood, no successful algorithms have been presented until now. In this paper, we are trying to challenge this sophisticated problem based on 3-D mathematical morphology and raster-vector hybrid processing. Two raster based algorithms for generating ordinary and constrained DTT have been presented, and their correctness and efficiencies also have been proven based on some experimental results.