Surface Model With Internal Holes In The Virtual Cutting Simulation Study

Virtual Cutting is applied in the field of CAD/CAM,Biology Simulation,Computer Graphics and Virtual Reality. Virtual cutting of triangle-facet has simple realization, realistic effect, and is real-time, convenience. In the paper, virtual cutting, the algorithms for face-triangulation and gridding connection are researched and realized with programming, and the simulation results are analyzed.The transferring vertices algorithm is introduced to cut the facet model on the base of traditional Sutherland-Hodgman algorithm. The algorithm makes sure the increment of the number of vertices is the least, so it has high efficiency, good responsiveness and no misshapen triangles. However, the transferring vertices may make the facet model distortion, so gridding subdivision is used to solve the problem. Gridding subdivision is the first step, and transferring vertices are used in the model to keep the shape of the model.It produces "empty" on the cut model, so face-triangulation is necessary. The cutting vertices form a polygon. It is easy for the convex polygon to solve with incremental insertion points. However, for the concave polygon is a little difficult, an algorithm for deleting triangles is presented in the paper. The algorithm has strong universality, not only solving convex and concave polygons, but also the polyhedron including the holes.In the reality, for example, gridding connection is operated in the virtual surgey, so the connection algorithms are studied in the paper, and two ideas about it are presented--adding vertices and no adding vertices. Lastly, adding vertices are realized with programming.This subject is developed with VC 6.0 and object-oriented programming thought is applied in the course of development, using the 3D model in the virtual surgery, because it has many facets and complex structure. The programming results show that the algorithm is effective and good simulation effect, so it has reality application value.At last, this thesis concludes the work of all the paper and points out the deficiencies and the development oriention.