Research And Implementation On The Algorithm Of LOD Model Simplification

Mesh model representation method is an efficient 3D object representation method. Now the computer technology has been widely used in military field, such as the navigation and identification systems of cruise missiles, automatic evaluation of attacking enemy's important objective systems. Systems for reconstructing battlefield in complex environment, and the 3D mesh models constructed and used in those fields are more precise and more complex. However, such complex models are not always available because they are difficult to store, to transmit, or to build. Only the other side, only important features of the geometrics and texture for the models need to be retained. It is applicable to have simpler versions of complex models in many cases. Model simplification is to provide approximate models of complex models by reducing triangles, edges and vertices and the simpler models, and to keep the basic geometrical shapes of the originals.These years, techniques of model simplification have become a hot topic and many efficient model simplification techniques have been provided by scholars from the army. However, mesh model simplification is a NP problem and the conflict between the simplification speed and the simplification precision always exists and there is not a simplification algorithm that can reach the optimal balance between speed and precision. A good simplification algorithm can reach the sub-optimal balance between speed and precision.At present, most of model simplified algorithms could not guarantee the visual characteristics of simplified models, resulting in serious visual distortion. To solve the issue, this paper presents a model simplification algorithm which maintains the geometry features of the model commendably by introducing a vertex curvature attribute factor. The simplification also keeps the texture features of model by signing the triangles with sharp color changes, and resolves the visual affection of the error accumulation by computing the data which in both the queue storing the edge collapse costs and the queue noting the changes of edges, so as to maintain the visual characteristics of the simplified model. Experiments show that the algorithm is efficient, reliable, and could maintain the visual characteristics of the model better.This paper has presented research in view of different kinds of model simplification algorithms. First, this paper introduces concepts and the simplified criterions which are related to the triangle grid models, and gives a detailed summary of the currently-used different kinds of simplification algorithms. Then, this paper elaborates in detail the thought and the simplification flow based on the geometry textural property LOD model simplification algorithm. Finally, the algorithm is verified with the VC++ programming, using DirectX 9.0 to realize the model to demonstrate, and experiments carries on the simplification to multi-group of grid models, so the validity of the algorithm is confirmed.