Research On Fast Collision Detection And Contact Body Compute For 3D Meshes

With the rapid development of mesh models & their application in Computer Graphics, Animation Multimedia, Virtual Dynamic Simulation, CAD/CAM, Mechanism and spatial layout, Collision detection is receiving more and more attention and gradually becoming one of the main 3D model characters extraction. It is now widely used in reverse engineering, animation, and mechanic manufacture fields. Among the mesh character distilling methods, collision detection is a basic and initial one. However, a diversification of mesh character application usually causes kinds of character extraction, while this produce a lot of problems for collision compute and character extraction in mesh objects.From the point of character extraction of 3D mesh, this paper presents several useful distilling methods. Meanwhile we further put up mesh construction way on the base of the character extracted before, so as to achieve results on both character extraction and mesh construction. In real application, we not only get the physical idiosyncrasy through mesh character or implement corresponding collision response, but also on the right time can construct needed mesh character or mesh models.The thesis tests a hierarchical representation of models using tight-fitting oriented bounding box trees (OBBTrees), and then computes the interference detection status amongst complex models undergoing rigid motion. On the basis of bounding box detect, mesh should be wrapped in the box and be judged through interval overlap methods as to get contacted boxes. Depending on the location relation between the triangles in contacted boxes, we can calculate contacted triangles and contacted lines between contacted triangles. To minimize the compute time and complexity of collision process, optimization is also used.Mesh character conformation after contacted is base of modelscharacter extraction. In view of specialty about mesh models extraction, through the sequence and location relation between triangles contacted, contacted lines in triangle can be constructed to contacted lines or loops in mesh. From the Oriented Bounding Box collision detection point, a bounding box inclusion algorithm is developed which test contacting and including. Therefore the triangles included in the other boxes can be judged by this way. Finally, the original contacted triangles combined with the included triangles in the process can implement the mesh body reconstruction.We also present mesh character retrieve and mesh contour body volume estimation methods based on the mesh character extraction and character construction representation in further applications.