The Research Of Mesh Conversion Algorithm And Complex Surface Reconstruction

Reverse engineering is a kind of digital product development technology, with the development of technology, more and more widely used in large size mould and complex curved surface design. The reverse modeling of mould is a typical application of reverse engineering, related research achievements play a more and more important role in mold development and repairing.The grid is a key step in the process of reverse modeling, which includes triangular and quadrilateral.Compared with triangular mesh, quadrilateral grid have a big advantage, and widely used in commercial reverse software; the surface reconstruction has important influence on effect of reverse modeling,however, complex surface reconstruction precision is not high.Therefore,in order to optimize the quality of reverse modeling and improve accuracy of the complex surface reconstruction,research of mesh conversion and complex surface reconstruction technology has very important significance.Thesis carries out research work mainly from these two aspects.Related technical methods of mesh conversion are studied,Proposing a mesh conversion algorithm of selection algorithm on the basis of region division.The algorithm firstly utilize region division to divide the grid model into flat area and the curve area on the basis of optimal triangular grid,and in different regions, respectively adopt the most appropriate selection of base section algorithm to determine the base section, on the basis of the base section to form quadrilateral,finally generate quadrilateral mesh.In the process of mesh conversion,using relatively good sequence of combination of tree local smoothing method to optimize local grid,and improving the quality of new quadrilateral elements and adjacent units.Surface reconstruction technology and the factors that affect the precision of surface reconstruction are studied.In the process of complex surface reconstruction,using a particle swarm optimization algorithm to solve optimization problem of high-dimensional continuous multivariate nonlinear,which occur during surface parameterization.Particle swarm optimization algorithm is able to solve the problem of multi-objective optimization, accurately calculate the surface control point, node vector, power factor and other parameters, creating favorable condition for the curvedsurface fitting.Reconstruction models’ main deviation range of point-surface between±0.27 mm,and adjacent surfaces meet criterion of G1 tangent continuation.Software is designed in this paper based on VS2008 platform, in MFC application framework, using c++ language and Open GL.The software has reading/displaying mould point cloud data, triangulation point cloud and other functions,with function of flexibly transform graphics orientation,zoom,reset etal,which are convenient to human-computer interaction.