PAR: A representation scheme for rotational parts

A new representation scheme PAR (Principal Axis Representation) for rotational parts is proposed as an internal representation scheme for Constructive Solid Geometry (CSG). The main idea of PAR is to represent uniquely an object by its principal axis and a set of boundary curves so that geometrical properties of the part can be easily computed. In his paper, the PAR scheme is first described and followed by a proof of its equivalence to the CSG scheme. Also proved is the uniqueness of the PAR scheme. Finally, an algorithm that converts a CGS representation into PAR is briefly discussed along with examples.