Research On The Construction And Visualization Of 3D Real-time Spatiotemporal Database

As the data foundation of the 3DGIS,3D real-time spatiotemporal data can enable users to intuitively obtain real city scenes.With the rapid development of cities and the continuous updating of 3DGIS,more and more abundant and accurate 3D real-time spatiotemporal data are urgently needed to provide technical support for urban management planning,but the current 3D real-time spatiotemporal database lacks 3D plotting function and the monomerization function of the building model,which have brought certain difficulties for the service of the 3D real-time spatiotemporal database in urban management planning.In order to realize the effective management of 3D realtime spatiotemporal data,this article took Tibet as an example,proposed a 3D real-time spatiotemporal database construction plan based on data integration;realized 3D plotting function and building monomerization for two different data sources,effectively solved the problem of the lack of data visualization function in the current3 D real-time spatiotemporal database.The main research contents and results of this article are as follows:(1)In order to effectively manage the 3D real-time spatiotemporal data of Tibet Autonomous Region,this article designed the construction process of 3D real-time spatiotemporal database.The process includes: firstly,implemented conceptual design,logical design,physical design,index design,and security design of the database,and then implemented check of pre-processing,data pre-processing,data storage and postprocessing of the 3D real-time spatiotemporal data,and finally constructed a 3D realtime spatiotemporal database.The built database can store and manage 3D real-time spatiotemporal data in different formats,which improved its practicability and security.(2)Based on the vector data in the task area,a 3D plotting method of vector and DEM data superimposed was proposed to realize the query and rapid positioning of the task area.This article reduced the response time of the algorithm and improved the efficiency of the algorithm by unifying the vector data format in the database;then obtained its plane coordinates by analyzing the vector data;in order to obtain the elevation value of the vector data,this article realized the vector data overlaying on DEM data to generate 3D plotting data based on the geometric method,and realized the function of 3D plotting.(3)Based on the oblique images in the task area,a method of building monomerization based on dense point clouds was proposed,which realized the individual query and display of key buildings.This article first separated ground points and non-ground points through point cloud filtering;then extracted building point clouds from non-ground points through point cloud classification;then extracted the top contour of the building from the building point cloud and fits its contour function formula.The building contour function was used as a constraint condition to obtain the point cloud data of a single building to construct a 3D model.Finally,a real and highprecision monomerization model was obtained through texture mapping.