Generating Cylindrical Representation Of Solid Objects From Surface Representation

An algorithm which converts a surface representation of three-dimensional objects to a cylindrical representation is presented. Given a surface representation which describes the topological relation among the faces, edges and the vertices of the objects, the algorithm generates an augmented quadtree which represents a set of square cylinders approximating the volume of the objects. The augmented quadtree is similar to the conventional quadtrees used to describe two-dimensional image regions except that the z-dimensional information of the cylinders is added to each node of the quadtree. This algorithm is described for polyhedral objects but can be applied to curved objects also. The complexity of this algorithm is proportional to the number of unit cells in the total projected images.