Based On The Surface Modeling Of Subdivision Study

Subdivision is a new method of discrete modeling. By defining the refinement rules of control meshes, subdivision surface can be considered as a method of surface modeling .With development of theory and widening scope of application, the subdivision surface modeling method has gradually formed its own independent disciplinary system. The surface modeling method is improved; a new subdivision surface modeling method is endless.At the same time, combined with some new mathematics theories, such as the wavelet, the multiresolution analysis and so on, it has obtained a strong vitality, and became one important free surface modeling method followed NURBS. Therefore, the surface modeling is an important element in the CAD, CG, it has a wide applications in the field of industrial technology. The exiting subdivision has been analyzed, their characteristic and their deficiency were summarized. Based on the linear algebra criterion that three vectors originating from a vertex being linear dependence are coplanar, a new adaptive subdivision scheme is presented. This method algorithm is simple and high efficiency (especially to massive data points), and the model processing speed is raised. Many instances had proven these methods have a very good application prospect..The vector and curvature are important characteristics of differential geometry; they described the triangular grid of the local geometry feature. They are intimately related to the precision of the subdivision algorithm, and are very significant in the position of surface modeling. A novel formula for the estimation of triangular mesh vertex normal vector is presented. Instead of area weighted, this formula is area and angle weighted. So, the flatness of vertex method by Wu JianHuang is improved. The formula considered size and shape of the triangular grid vertex of the impact of vector, so that the vertex vector of the results are more accurate and the algorithms have been optimized.Wavelet is a multi-level function, it can be used the mathematical tools for decomposition and reconstruction, multiresolution analysis is carried out by the wavelet transform. This article will integrate wavelet transform with subdivision, using a wavelet post-processing for the three-dimensional model while 3-D will not be affected graphics display, That is farthest minimize the amount of data and improve the subdivision and reconstruction efficiency.