Research On The Algorithm Of Hole Repairing In 3D Point Cloud Model

The protection and restoration of ruins, human remains and other cultural relics is an important area of digitization of protection research. Due to Factors such as natural corrosion, unearthed procession and vandalism, let many cultural relics have defects such as damaged, holes, fragmentation, it has brought tremendous obstacle to its identification, recovery, repair work. Three-dimensional model as an important tool for digital protection, have widely used in the virtual rehabilitation, repair and display. At home and abroad, three-dimensional point cloud algorithm has become a hot topic.However, existing patching algorithm do not consider the local characteristics of the area to be repaired, the overall of patched results is poor, the robustness of the algorithm still to be improved. To solve this problem, this paper has done the following work:First, in-depth comparative analysis the patching holes algorithm of three-dimensional model at home and abroad.according to the three main features of holes, namely:The hole which is formed by the lack of data sets, jagged hole in the face of complex and three-dimensional model of occlusion of the hole, construction area weights hole patching architecture, according to the different characteristics, implementation the regional division structure. Compared with existing holes algorithms, this new division algorithm can better adapt to the model of different complex surfaces.Second, to improve the three-dimensional minimum space cut algorithm based on the theory of octree, to complete the automatic zoning of the three-dimensional point cloud model, and principal component analysis will be used to three-dimensional model dimension reduction, compared to the existing minimum space cut algorithm, the proposed method adapt to changes in the lager curvature of complex cutting surface better, and has better robustness and higher cutting efficiency.Third, we proposed a three-dimensional model automatic hole patching algorithm based on a triangular lattice structure:weighted grid (Mesh-Weight) method.After the pre-processing is completed, firstly, the method let the image down to the smallest space grid area and to vertex split region, and according to the neighborhood correlation of factors and weights to fill the optimal connection path merit-based selection path.The algorithm combines the features of greedy algorithms, divide and conquer, iterative ect, it is a complex patching algorithm. Fourth, on the basis of the weighted mesh algorithms, design and implement a three-dimensional model of patching holes system, including import and export 3D point cloud data file, hole detection, meshing, regional grid filling, smoothing, rendering and other functions.The proposed grid weighting algorithm is applied to patching holes in the three-dimensional model contains large pores, the repair effect is satisfactory, could adapt to complex surface holes form, and verify the regional weights pre-processing integrity of the system.