Trimming of free-form objects for a B-Rep solid modeller

This paper describes a technique for trimming solid objects in a B-Rep solid modelling system. A B-Rep scheme based on the split-edge structure, which is suitable for the representation of trimmed surfaces, is first discussed. Algorithms for graph traversal, graph merging and graph splitting are then given in detail. Based on this B-Rep scheme, a technique for trimming objects is developed. The trimming process involves the evaluation of surface intersections, graph cutting along intersections and merging of appropriate graphs to obtain the required trimmed objects.