Triangular Mesh Reconstruction Based On Point Cloud In Reverse Engineering

Reverse engineering is the hottest technology in the CAD/CAM area, which is based on 3D scanning techniques and geometric modeling technology. The 3D scanning makes it possible to get the digital model of objects with arbitrary topology types, and the digital models meet various application requirements. The geometric modeling technology provides the theories and methods for representing and constructing kinds of curve and surface models.In geometric modeling, there are several representations and models , such as point cloud, triangular mesh and parametric surface .Point cloud has the advantages in presenting objects with various topologies and easy for bool operations. Triangular mesh captures original object topology , linearly approximates the object geometry with simple representation , and becomes one of representation standards for geometric design systems. The design of parametric curves and surfaces plays an important role for long time in computer aided geometric design.Benefited from the development of surface reconstruction algorithms , we have realized an algorithm to reconstruct a manifold mesh from unorganized point cloud with efficiency ,robustness and flexibility ,which are experimentally demonstrated by various examples. Topological operations and the data structure make it sure to incrementally build a triangular mesh with topological integrity.We have also realized a set of three elementary mesh transformations, edge collapse, vertex collapse, and edge swap, and defined the legal condition for the three transformations. At last a mesh optimization algorithm is realized to minimize the differences between the estimated curvatures of the triangle mesh and the object surface. The example demonstrates the ability of strong convexity recovery of sharp edges.