Automatic restoration method of three-dimensional digital geometric grid model structure

Abstract

The invention discloses an automatic restoration method of a three-dimensional digital geometric grid model structure. According to the method, three-dimensional digital geometric grid models of random structures are converted into watertight two-dimensional manifold three-dimensional digital geometric grid models meeting 3D printing requirements. The method mainly includes the following steps that voxelization is carried out on input grid models, the models are converted into body representation forms piled by voxels from polygonal grid forms, and the obtained voxels are signed as internal voxels, external voxels and boundary voxels; each calculation unit including 8 adjacent voxels is analyzed, a mode of a surface patch generated in each calculation unit is determined according to the number and relative positions of the internal voxels, external voxels and boundary voxels of the each calculation unit, and the surface patches form output grid models; defect structures in the output grid models are detected and restored, normal vectors of the surface patches in the output grid models are rectified, the output grid models are calibrated by means of the input grid models, and the final output grid models are obtained.

Description

technical field [0001] The invention relates to a method for repairing a structure of a digital geometric grid model, belonging to the field of computer graphics, in particular to a method for automatically repairing a structure of a three-dimensional digital geometric grid model based on volume representation. technical background [0002] With the development of 3D scanning technology and 3D modeling technology, we are in a period of explosive growth of 3D models, the most widely used of which is 3D mesh model. However, due to the various sources of 3D models (such as remote sensing, medical scanning, CAD, etc.), there are huge differences in the structure of 3D mesh models, which in turn limits the analysis and reuse of mesh models. For example, most grid model processing and analysis methods, such as geodesic nearest neighbor calculation, finite element analysis, rasterization, surface smoothing, model simplification, etc., require the input grid model to be a manifold g...

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Problems solved by technology

However, the literature used for face extraction 6: Lorensen, William E., and Harvey E.Cline."Marching cubes: A high resolution3D surface construction algorithm."In ACM Siggraph Computer Graphics, vol.21, no.4, pp .163-169. The Marching Cubes (MC) algorithm proposed in ACM, 1987. has ambiguity in some cases of face extraction; at the same time, literature 7: Newman, Timothy S., and Hong Yi."A survey of the marching cubes algorithm."Computers&Graphics30, no.5(2006):854-879. pointed out that although there are methods to resolve ambiguities in MC algorithms, these methods not only require users to choose different solutions for the ambiguities that appear in the model, but also Greatly increased the time complexity of the MC algorithm

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