Research On The Mesh Optimization And Geometry Reconstruction Of Deformation Surface Based On Pro/E

Technology of Surface Reconstruction is an important one in CAD research and application. This dissertation studies the surface reconstruction technology in virtual CAD and the relevant bases such as virtual reality mesh modelling and mesh optimization.Chapter 1 (the introduction) gives a review of the development situation in virtual deformation design and surface reconstruction research and application. In this background, the significance and contents of mesh modeling , mesh optimization and mesh surface reconstruction in virtual environment are proposed particularly.Chapter 2 presents a deformation-and-reconstruction-oriented virtual design model, which includes the representation of part attributes, surface character relationships. A milti-hierarchical pan model is used to describe the part character and geometry information. Based on this milti-hierarchical model, application method for information organization of part is presented.Chapter 3 proposes a new rule of Arbitrary Maximum Angles of Chord for triangulation and locale optimum, which avoides Calculating angles of conventional methods in mesh simplification. Moreover, with the introduction of arithmetical average windage concept, optimum method for the boundary mesh retriangulations is presented.Chapter 4 discusses the usage of two basic geometric reconstruction method (Bezier and B-Spline surfaces reconstruction) in virtual CAD system based on the milti-hierarchical mesh model. Bezier reconstruction method introduces Li Lixin's new C-T algorithms which adopts Bezier patches on rectangles. B-Spline reconstruction follows Floater's Shape-preserving Parametric method using double cubic B-Spline surface and extends it into non-four-side areas by inducing corner vertices and optimizing the sheer-shape boundary which amends the boundary distortion of the reconstructed surfaces.With the theory and methods in this dissertation, chapter 5 introduces the reconstruction model in VDDS-CAD(the Virtual Deformation Design CAD System), coming up with some examples of surface reconstruction.Finally, conclusions were drawn from this dissertation with recommendation for future research in chapter 6.