Research On The Intersection Of Cellular Adaptive Subdivision Surface And Plane

The technology of cell adaptive subdivision surface with plane intersection is an important research direction of CAD/CAM,and it has been widely used in NC machining,rapid prototyping and other fields.In recent years,many scholars have done technical research on the intersection of complex subdivision surfaces,and achieved some results.However,at present,the intersection technology of plane and subdivision surface is only limited to subdivision surface of common data structure.When subdivision surface of common data structure intersects with plane,there is a large amount of data at the intersection point,and it cannot guarantee efficiency and stability at the same time.The technique of cellular adaptive subdivision surface intersection can efficiently calculate the intersection point of cellular adaptive subdivision surface with special topological structure,but there are few reports about the technique of cellular adaptive subdivision surface intersection with plane.So based on the cellular data structure to realize adaptive subdivided on the basis of subdivision surface,combining with the divide and conquer strategy,through the AABB bounding box and multilevel segmentation technology,and the rest to the adaptive subdivision surface another plane intersection,thus put forward plane and cell scattering detection method of adaptive subdivision surface.The main contents of this paper are as follows:(1)Analyze the basic principle of Catmull-Clark subdivision surface model construction.The subdivision rules of Catmull-Clark were used to construct the Catmull-Clark subdivision surface model,and the segmentation representation of Catmull-Clarksubdivision surface was realized by studying the cellular data structure.The limit vertex positions were calculated and the limit vertex method was used to construct the limit grid representation of the subdivision surface model.It lays a foundation for the analysis of cellular data structure of adaptive subdivision surface and the intersection of cellular adaptive subdivision surface and plane in the following paper.(2)Topological structure analysis of cellular adaptive subdivision surface surfaces under multiple metric criteria.Judge subdivision surface calculated by using a variety of measurement criterion of flat areas with the flat area,to eliminate cracks after constructing automata adaptive subdivision surface,and analyzes under the rule of multiple measures of the characteristics of the topology of the adaptive subdivision surface,pointed out that through cellular data structure constructed a variety of adaptive subdivision surface state grid vertex similarity.(3)The intersection technique of plane and cellular adaptive subdivision surface is studied.By using the cellular data structure of the adaptive subdivision surface,the global intersection problem of the adaptive subdivision surface is transformed into a local intersection problem of the surfaces of the adaptive subdivision surface,and the disjoint surfaces are quickly eliminated by using the divide-conquer strategy of AABB bounding box and multi-level segmentation technology.The intersection of the plane and the adaptive subdivision surface is completed by calculating the first intersection point and judging the type of intersection line,calculating the subsequent intersection point and judging the termination intersection point,and the intersection technology of the plane and the cellular adaptive subdivision surface is analyzed.The test and analysis of the algorithm show that the method in this paper can realize the intersection of cell adaptive subdivision surface and plane.Results show that under a variety of measurement criterion of cellular adaptive subdivision surface and plane intersection technique significantly improves the computing performance,adaptive subdivision surface intersection technology overcome the disadvantages of existing methods,has the characteristics of stability and rapidity.