DESIGN OF IGES PRE-AND POST-PROCESSOR BASED ON SURFACE MODEL

Most CAD systems have surface model conforming to IGES standard as their input／output interface．In this paper，we design a pre-and post-processor of IGES surface model based on Trimmed NURBS patches，and also give an algorithm for transform between solid model and surface model．In the transformation from surface model to solid model the open edge structure is used to realize surfaces topologic information regeneration．