GENERATION OF UNIFORM EXPRESSIONS FROM CSG NONUNIQUE REPRESENTATIONS

Non-uniqueness of the tree representations is a well-known problem in feature extraction from the output of a CSG solid modelling system, Th ree main causes of the problem ate examined and the most commonly occu red one is dealt with in this paper. Based on the achievement of posit ion relationships between orthogonal primitive objects, an approach fo r solving the non-uniqueness steming from multiple definitions for an identical object is detailed, To demonstrate die methodology of the ap proach, an object with the machining feature of a square slot is illus trated.