Research On Implicit Surface Reconstruction Technology Of Point Cloud Model

The surface reconstruction technology constructs digital geometry model by using point cloud information on the surface of sampling objects.It has been a hotspot in the field of virtual reality and computer simulation.With the rapid development of 3D scanning technology,people can obtain millions of sample points by using high precision 3D scanner,which makes it possible to construct high quality digital geometry model.However,the problems such as huge number of points and noisy points make the surface reconstruction become a difficult work.Recently,function-fitting method based on implicit surface has been an important way for surface reconstruction,which has an obvious advantage comparing to traditional ways.In this paper,we present a hierarchical adaptive implicit surface reconstruction algorithm according to the existing algorithms,including calculation of impilicit surface function and function visualization.The main contents in this paper contain three following aspects:1.The research on basic work for implicit surface reconstruction of point cloud.Firstly,we introduce the geometric properties of point clouds,including neighborhood search algorithm of point cloud,normal vector estimation of point cloud,normal vector orientation adjustment algorithm and curvature calculation method.Then we introduce the theoretical basis of implicit surface reconstruction,analyzing the advantage of implicit surface compared to other mathematical expressions,and formulate the process of implicit surface reconstruction.Finally,we introduce the least square method which is the surface fitting method during reconstruction.2.Having analyzing the classic surface reconstruction algorithm,we present an implicit surface reconstruction algorithm based on adaptive octree.It mainly calculates implicit surface function by function fitting based on original sample points,including establishing octree hierarchy structure of point cloud,calculating normal vector of sample points and adjusting orientation,fitting local points cloud by the least square method in order to calculate local function of octree leaf nodes,blending local functions by partition unit to obtain global implicit surface function,i.e.mathematical expression of model.Finally,we extract zero isosurface by meshing algorithm and draw mesh model.The algorithm can obtain higher quality mesh model compared to traditional algorithms.3.Based on implicit surface rendering algorithms,we present a hierarchical implicit surface rending algorithm,which extracts the zero isosurface of implicit surface function to generate the triangle mesh model.It mainly includes subdivision of sampling data space,generating voxel cube,selecting initial voxel,generating triangular mesh inside voxel using implicit surface function,selecting the adjacent voxels for triangulation,finally generating closed triangular mesh model.The algorithm generate mesh model with different subdivision,which satisfies the need for precision of model in different virtual scenes.According to the above research,this paper has realized the implicit surface reconstruction algorithm of point cloud model,and has verified the correctness and robustness of algorithm by testing different point cloud models.