Sphere-tree construction using dynamic medial axis approximation.

Abstract

Collision handling is very computationally expensive, especially in large scale interactive animations. Hierarchical object representations play an important role in performing ef?cient collision handling. Many different geometric primitives have been used to construct these representations, which allow areas of interaction to be localised quickly. For time-critical algorithms, such as interruptible collision detection, there are distinct advantages to using hierarchies of spheres, known as sphere-trees. This paper presents a novel algorithm for the construction of sphere-trees. The algorithm presented approximates objects, both convex and non-convex, with a higher degree of ?t than existing algorithms. In the lower levels of the representations, there is almost an order of magnitude decrease in the number of spheres required to represent the objects to a given accuracy.