Research On Urban 3D Real Scene Modeling And Rail Line Design Method Based On Oblique Photography

The urban rail transit routes mainly pass through the bustling downtown area.The high-rise buildings in this section are rich with deep foundations and laying of underground pipelines.If the design of the circuit scheme is unreasonable,it will greatly increases the construction difficulty and investment cost,affects the surrounding environment and reduce the overall economic and social benefits of urban rail transit.In the traditional design process,it is difficult to find potential conflicts based on two-dimensional drawings.It requires multiple feedbacks and modifications from internal and external industries,and it is easy to create design flaws and omissions.The virtual reality and 3D visualization technology can realistically restore the complex three-dimensional environment of the city,and can intuitively observe and judge whether there is any conflict between features and lines.Therefore,based on the 3D visualization design of 3D geographic information platform,the paper deeply studied the modeling methods of urban scenes and underground pipelines.Combined with the horizontal and vertical design of the line,the 3D planning and design system of urban rail transit lines was established.And the 3D virtual environment of urban ground and underground,three-dimensional design of urban rail lines and related spatial analysis functions was realized.The main research contents and achievements of the paper are as follows:(1)Rapid modeling of urban scenes.This paper analyze the advantages and disadvantages of the existing "Digital City" modeling,and systematically studies the methods and principles of rapid modeling of urban scenes.Based on the sloping photography modeling technology,ContextCapture tilt photography modeling software was used to import aerial image data,and its dense matching technology was used to extract high-density point cloud to realize the fast construction of the whole element city scene.The singulation based on point cloud cutting is realized,and it is possible to realize the automatic spatial analysis of buildings under the inclined photography environment.(2)Modeling of underground pipeline.In view of the abstract geometric characteristics of underground pipelines,the data structure of underground pipeline networks is systematically studied,and the modeling of underground pipeline networks is solved.It realized three-dimensional display of underground pipelines under the underground mode and excavation mode as well as the query of pipeline attributes and provided basic data for spatial analysis.(3)Three-dimensional design of urban rail transit lines.In this paper,the design principle and method of urban rail transit line are studied systematically,and the design system of urban rail transit which is developed by our laboratory is used to realize the circuit designing and three-dimensional modeling in real three-dimensional scene.It provides a visual reference for evaluating the advantages and disadvantages of the circuit scheme(4)Study on the spatial analysis method of the circuit scheme.Based on the circuit design scheme,the buffer generation method and the buffer analysis algorithm were studied.The building demolition statistics and underground pipeline relocation statistics of the area covered by the line plan were realized.Combine buffer analysis with urban rail transit lines to automatically determine the spatial relationship between the line and the surrounding objects,thereby improving design efficiency and design quality,and reducing the designer's work intensity.