Research And Implementation Of Triangulation For Scattered Data Points In Reverse Engineering

With the development of the modern design and manufacturing technology, as well asthe computer technology, Reverse Engineering is widely used in the field of mechanical,motorcar and mold engineering. Triangulation of scattered data is the first important step andthe base of later step of reconstructing curved surface in Reverse Engineering. Meanwhile,with the recent development of 3D data collection technologies and hardware facilities(e.g.laser and CMM), the higher requirements of authenticity, real time and interaction ofcomputer graphic visualization, the demands of CAD/CAM and other quick moldingtechnologies, the technology of triangle mesh generation and simplification have become oneof the hotspots in the field of 3D reconstruction.Closely combining with the requirement of developing a new generation of surfacereconstruction in Reverse Engineering with superior performance, this paper studies the keytechnology of triangulation of scattered points and realizes the process. The main tasks of thisthesis are the following:◆An introduction on concept and general researching situation of Reverse Engineering andtriangulation is conducted. In the meanwhile, combining with the task, a study is carriedout upon the common triangulation method of scattered data points.◆Based on the Delaunay triangulation method, an improved triangulation mesh generationalgorithm for arbitrarily planar regions is presented. This algorithm has the advantage offast operation, adaptation to complicate boundaries, high quality mesh. The algorithmincludes rank of scattered points, triangulation and mesh optimization. At last, an exampleis given to demonstrate the reliability and practicability of this algorithm.◆A new 3D triangulation method based on boundary extension is proposed. Thetriangulation processes start with selected seed triangles, the triangular meshes extendoutward by continuously linking the most suitable points to them along the boundaryedges of the meshed area. Data points of some non-convex complex object surface suchas object with interior holes can be directly triangulated without manually dividing it intoseveral convex patches. The application results indicate that this approach is feasible andefficient in modeling of 3D point cloud. ◆Based on the previous algorithm, a triangulation system is integrated and designed.Object oriented software development method is being adopted. The function, structureand realization method of software system are given out systemically. Aimed at thedeveloping trend of CAD/CAM software and with adopting of fashionable Visual C++,OpenGL language, the testing software is being developed. A preliminary foundation hasbeen laid for the development of Triangulation software with superior property.A preliminary test which has been carried out upon the software developed in this papershows that this system operates normally and basically reaches the requirement of design.