3D anisotropic grid generation with intersection-based geometry interface

In this paper we present a new interface for geometry description. This interface is based on four intersection routines. It allows to use geometry description without explicit boundary description, for example using characteristic functions and boolean operations. This seams to be useful especially for time dependent geometries. We show how to create and change this geometry description, and how to use this interface for grid generation. We discuss grid quality criteria and possibilities to create and manage anisotropic grids. At last we describe an algorithm for 3D grid generation based on this interface which was implemented by the author. This algorithm combines an octree-like re nement process, shift of nodes to the boundary and Delaunay grid generation.