Spheres-to-voxels conversion

The use or prototyping of volumetric representation schemes based on three-dimensional cells-typical examples are the cubic frame buffer (Kaufman and Bakalash, 1988) or the octree (Meagher, 1982) schemes-often requires the availability of efficient routines for converting elementary solid objects into cells. In this note we present a conversion algorithm from spheres to voxels. It accepts as input the definition of a sphere (in terms of its radius and center) and returns the set of voxels completely or partially contained into the space bounded by the surface of the sphere, that is, a 3D scan conversion of the sphere.