Triangular Mesh Model Simplification Technology And Level Of Detail Model

Three-dimensional (3D) mesh models have gradually entered into the production and life of people as a new medium type, applied more and more widely in many domains, such as virtual reality, animation games and production. While the accuracy of these 3D mesh models grows with the development of the 3D scanning and modeling techniques, the total data of the models soared rapidly as a result. That brings great pressure to the rendering, transmitting and editing systems of computers. One way to solve this problem is to simplify these complex 3D models and to perform multi-resolution modeling, accordingly reducing the data, accelerating the process speed and sparing storage space by replacing the original complex model by a simple one. Apparently, the discussion of simplification of 3D mesh models is a valuable research direction.At first, the introduction of the model simplification technology's origin, research content, as well as its significance and application domain is presented in this paper. Then the method of reconstruction of triangular mesh model from point cloud data is discussed. Current domestic and foreign approaches of triangular mesh model simplification are analyzed and researched, including the static and dynamic simplification algorithms. The introduction of common methods of error measurement metrics is followed. Subsequently, the edge collapse algorithm measured by quadric error metrics is particularly discussed, including the discussion of the theory of quadric error metrics, the definition of edge weight, the process of model simplification and the optimal position of the new vertex. This approach implements the static model simplification effectively and preserves the geometry shape of the original model intactly.Due to the fact that the static model simplification could not implement the multi-resolution in one single model, in this paper a dynamic model simplification approach, progressive meshes (PM for short), is emphasized. Paper introduces the theory and the process of progressive meshes, presents the legal collapse condition, and discusses the ambiguity caused by vertex split and its solution. This approach distributes a weight for every edge, reflecting local geometry shape including edge length, curvature of the vicinal model and triangle shape, which is compared with others to decide the order of edge collapse. Aimed at view-dependent multi-resolution model conformation, paper constructs a compact and flexible multi-resolution data structure for expressing the simplified triangular mesh model, in...