Research On Urban 3D Modeling And Application Based On Tilt Image And Point Cloud Data

With the continuous development of UAV technology and three-dimensional laser scanning technology,geographic information data acquisition methods are becoming more diverse,and the current situation and accuracy of data have been further improved.With its intuitive and efficient advantages,three-dimensional technology of urban reality has gradually become an important means of urban geographic information data expression.Because of the large undulating terrain and the large number of buildings in mountainous areas,there is no systematic research plan for the establishment of the three-dimensional urban scene model in Changsha.Based on tilted image data and point cloud data,this paper makes relevant research and Analysis on the construction of three-dimensional scene model in Changsha City,puts forward corresponding three-dimensional model construction scheme according to different types of modeling areas,improves the traditional roof contour extraction algorithm,and uses WebGL technology to design and develop the prototype system of three-dimensional model management platform in Changsha City.The main work of this paper includes:(1)This paper summarizes the research background and significance of three-dimensional urban scene construction technology,systematically analyses the research status of three-dimensional model construction technology and WebGL technology,lists and compares the advantages and disadvantages of the main three-dimensional construction methods,summarizes and collates the main application scope of three-dimensional urban scene technology,and puts forward the key and difficult points of current research in this field.(2)In this paper,a three-dimensional model construction scheme for Changsha City is proposed systematically based on inclined image data and point cloud data by using the method of zoning three-dimensional model construction.The process of building the three-dimensional model of the main urban area of Changsha is improved.Aiming at building the three-dimensional model of the buildings in the mountainous area of Changsha,the commonly used roof contour extraction algorithm is improved.A classification algorithm for extracting the roof point cloud data based on the discrete degree of the point cloud data is proposed.The experimental results show that compared with the extraction algorithm using the minimum curvature as the threshold directly,the extraction result of this method is better.(3)This paper classifies the data types in urban three-dimensional scene,constructs the organizational structure of urban three-dimensional scene data,designs the hierarchical structure of Changsha three-dimensional model management platform,and puts forward the classification standard of model grade.This paper studies the interactive operation of urban three-dimensional scene data based on WebGL technology,and analyses and explains the algorithm ideas of interactive operation such as three-dimensional rendering,flight roaming and visual field rendering in WebGL web pages.(4)The three-dimensional model management platform of Changsha City based on WebGL technology is designed and implemented.The system structure framework and system functions are designed.The data release and data call of the system are introduced.The results of the related system functions are displayed.