Study On Subdivision Surface Fitting Base On Mesh Simplification

The key and difficulty of reverse engineering (RE) are reconstructing complicated surface. At present time, the common surface reconstruction techniques can only deal with a surface of simple topological type. In case of complex topology, it is difficult to hold continuity among neighboring surfaces. The use of subdivision surfaces provides a promising alternative approach for modeling shapes with arbitrary topology.Subdivision is one of the most active research topic in geometric modeling, especially surface design in current years. It is comprehended more and more profoundly by researchers with complete establishment of continuity analysis theory of subdivision surfaces, incessant emergence of new schemes and extensive applications of subdivision techniques to multiresolution representation of 3D models, computer animation, digital geometry processing and so on. As for their applications, techniques for computer graphics, for example, multiresolution representation based on subdivision approaches, are relatively more successful in contrast to reconstruction, fitting, and processing CAD oriented. This thesis discusses construction of subdivision schemes and fitting of subdivision surfaces. Major contributions list as follows.1. A new mesh simplification algorithm is proposed. The new method bases on half-collapse, taking the real distance from the point to the triangle as error distance, and combine the sharp degree, implements fast and it keeps models'sharp features well.2. Base on the mesh simplification algorithm proposed in the paper, a way to build PM is designed, which can be used to construct LOD models.3. An adaptive Loop subdivision method preserving sharp feature is proposed. Combining with the mesh simplification algorithm, a novel method for generating multiple LOD models is obtained.4. A new subdivision surface-fitting algorithm based on mesh simplification is present in the paper. Be different from other methods which through resolving fitting equations to get the control mesh, the subdivision surface is obtained by adjusting, optimizing, identifying features and adaptive subdividing the control mesh, this method makes subdivision surface approach to the originality data.