Research On Simplification And Repair Algorithm Of Three-dimensional Model

With the development of 3D information acquisition equipment and modeling technology,three-dimensional model has become an important digital media.3D model has made a wide range of applications in many fields,such as 3D games,cultural relics protection,film and television animation and virtual reality.The more detailed the mesh model,the more detailed the characteristics of the physical model,but this means that the polygons of mesh model is also numerous,which brought great pressure on computer storage,computing and visualization.However,such high-precision mesh models are not required in all scenarios,so according to different needs,it is necessary to simplify 3D model.At the same time in the process of collecting data,due to the existence of defects in the object itself,as well as constrains of data collection equipment,resulting in the original data is not complete.Finally,the reconstructed model will have holes,so the hole repair operation is needed.The main research goal of this paper is the simplification and repair algorithm of3 D model.Through deep analysis of the existing algorithm,the corresponding improved algorithm is put forward.The specific research work in this paper mainly includes the following aspects:(1)Introduce the research background and significance of simplification and repair algorithm.Analyze the research status of the two types of model processing algorithms at home and abroad in detail.Master the basic theory of grid model processing and related concepts.The existing error measurement method is summarized.And study common simplification and patching algorithms.(2)Based on the research of existing repair algorithms,an algorithm for restoration of feature information of hole area is proposed.The traditional repair method is easy to lose shape information of the central hole.Therefore,this paper adopts the idea of advancing to the center of the hole.The algorithm first detects the holes in the input model,then inserts discrete vertices near the boundary of the holes and triangles them.Next constructs an implicit surface with discrete points to fit the new grid.And finally restore the sharp shape information.The experimental results show that the proposed algorithm can repair holes well,and hole grid generated by the algorithm has high quality.(3)Summarize the simplification criteria of simplified algorithm should follow.On the basis of the existing algorithms,a grid simplification method for triangularelement deletion is proposed.The algorithm introduces the concept of the median value of the triangular patches.By calculating the angle between the area of the triangular facets and the normal vector of the first-order neighborhood triangle,the triangular facets are removed by the difference coefficient.Combined with the hole repair algorithm to repair the holes generated on the mesh surface.Finally,the hole mesh is subdivided,optimized and smooth.The experimental results show that the algorithm can effectively simplify the original grid model.Through error estimation of model before and after simplification,the error of the algorithm is smaller than that of the contrast algorithm.