3D Modelling Based On Voxels For Buildings Derived From Oblique Photogrammetry

The 3D reconstruction and representation of models has always been one of the important parts and core issues in surveying,mapping and geo-information.With the rapid development of modern geo-information industry,digital cities,smart cities,BIM and the like,have more and more demand for accurate 3D models of single buildings.At present,the technology of oblique photogrammetry is an effective means to quickly obtain 3D data of cities.But in terms of application,this technology still has obvious deficiencies.To be specific,the quality of the data,which shows its direct result,is usually not satisfactory.Such data needs to be organized artificially,so the efficiency of obtaining single models is still low.The main reason is the lack of directly connectable model elements between automated 3D reconstruction and manual modeling.Considering the existing technological means,traditional modeling driven by CSG or B-rep model lacks the ability of automation.In order to solve this problem,this paper attempts to introduce voxels driven by both data and models to connect 3D reconstruction and manual modeling,and proposes a reconstruction and optimization scheme for building models derived from oblique photogrammetry with voxels as their basic element,which can be used for reference by relevant researchers and engineers in this industry.The main content of this thesis is as follows:1)In view of the characteristics of direct grid model structure and voxel data of oblique photogrammetry,this thesis puts forward an optimization scheme for building models with voxels as their basic element.2)It designs a technological scheme covering from the grid data of complete scenes and to single voxelized buildings.3)It designs a scheme to optimize models restrained by linear segment structures based on photogrammetry,to solve the problem of rough models after automatic voxelization.This scheme is only for images,and don't need to edit the models directly and manually.4)It summarizes a principle of preference for texture for voxel models according to the production logic of data measurement,and designs a scheme of texture mapping based on small facets in accordance with this principle.It is proved by experiments that the technological scheme designed in this thesis can achieve ideal results of model reconstruction and optimization when dealing with right-angled flattop models.