METHOD OF COMPUTER-AIDED DESIGN OF A MODELED OBJECT HAVING SEVERAL FACES

摘要

The invention is directed to a method of computer-aided design of a modeled object (10) having several faces. The method comprises a step of identifying, for each of said faces of the object (10), at least another of said faces related to said face according to geometrical criteria. Faces are thereby marked as connected. This is part of the "topology preprocessing" needed for implementing subsequent steps of the method. The method also comprises a step of computing a plurality of points forming a tessellated representation of each of said faces. Based on this tessellation, the method characterizes critical regions by determining and storing data representative of an intersection between a three-dimensional geometrical figure (touching a given face) and a face related to said face, according to the identifying step above. The step of determining whether intersections occur is carried out for each point of the tessellated representation of a face and for each face of the object. Then, as part of a "frontier extraction" general step, the method computes frontiers (delimiting zones where surface recomputation would occur) between points according to their respectively stored data and determines zones according to the determined frontiers. Preferably, a progressive zone determination method is implemented; notably comprising detection of zones comprising fillet or round-like, step-like and wall-like sections, by calling a suitable coupling routine. Finally, surfaces (12, 14, 140, 142, 145, 148, 150) are recomputed according to the determined zones.