Large-scale Oblique Photogrammetry Data Dynamic Loading Technology For 3D Web Visualization

With the rapid development of oblique photogrammetry technology,drone technology and 3D reconstruction technology,the production speed of oblique photogrammetry data has been greatly improved in a wide range of scenes.Meanwhile,the information provided by two-dimensional images is far from meeting people's needs and facing the needs of three-dimensional visualization more and more.Although there have been many advances in the research of 3D web visualization,there are still many problems in the visualization of massive oblique photogrammetry data.For example,in the hierarchical data loading,the status of each level of data cannot be effectively controlled,the multi-area data cache management lacks corresponding research,and the traditional data cache management for a single area cannot solve the requirements of multi-region data management,When the image topographic data and the oblique photogrammetry data are uniformly loaded,the redundant image tile requests excessively affects the user experience.In view of the above problems,this thesis conducts research on the technology of loading massive oblique photogrammetry data in the three-dimensional web environment.The specific work has been completed as follows:1.By analyzing the traditional massive oblique photogrammetry data processing and the asynchronous loading of browser data,a strategy is proposed to control the data from coarse to fine,and each level of data loading can be effectively controlled.The data visualization draws a smooth transition from coarse to fine;2.In order to solve the problem that the traditional cache management technology cannot cope with the multi-area oblique photogrammetry data cache management,the related algorithms of data dynamic loading in the process of visualizing the tilted photogrammetry data are analyzed in depth,and a multi-area data cache dynamic is proposed.Management method,which is managed by each area cache,the amount of data of each area cached data is collected in a centralized manner,and the result of centralized data collection of the cached data determines whether or not the cache clearing mechanism is triggered,thereby implementing multi-area data caching.Dynamic management;3.In order to alleviate the problem of redundant image tile request when the image data and the tilt photogrammetry data are uniformly loaded,a dynamic loading technology of image tile data for 3D web visualization is proposed.That is,according to the coverage of the loaded oblique photogrammetric data,the image tile covered by the oblique photogrammetry data is judged,and the covered image tile data will not be loaded,thereby reducing the performance loss caused by processing the data request.This thesis realizes the visualization of massive oblique photogrammetry data,providing a solution for the visualization of massive oblique photogrammetry data.