Research On 3D Modeling Method Of Urban Rail Route Scheme Based On Oblique Photography And GIS

The rapid growth of China`s economy has gradually improved the construction and improvement of infrastructure.As an important component of urban infrastructure,rail transit is of great significance for improving the operational efficiency of cities,alleviating traffic congestion,and optimizing the use of urban space.Rail transit construction has been included in the strategic planning.Until now,many cities have completed the construction of the road network,and the lines have gradually expanded to the suburbs.At the same time,the rapid development of information technology has promoted the transformation of the urban rail transit design industry from the traditional model to digitalization and informatization.Therefore,this article attempts to use tilt photography and 3DGIS technology to establish a three-dimensional environment to assist the visual display of urban rail route solutions,and realizes the urban 3D scene and underground 3D virtual environment,3D rail track modeling and related spatial analysis functions.The main research contents and achievements of the paper are as follows:(1)Learn the basic principles of tilt photogrammetry technology,and use the software developed based on this technology to build an urban space model.By comparing the modeling software related to photogrammetry technology,using Bentley`s Context Capture application,the city`s oblique image data is loaded to automatically perform the empty three solution,generate a point set with extremely high density,and construct the high-density point set as a triangular patch After splicing the mesh model,each patch matches the corresponding texture in the image data to generate an urban space model.Through professional repair software,the model is refined and reshaped and singulated.(2)3D modeling of urban underground pipelines.Study the data structure of pipelines in underground space to complete data storage,Use the Skyline application program interface to call the database to draw the pipeline of the underground space.The vector data of the pipeline is used to determine its spatial position and attitude.The Cylinder / Box in the Skyline program interface can draw the model of the pipe body and the simple connection point at the corresponding position according to the attribute information.More complex connection points use 3D Max The software is created independently,and then the model is imported through the Create Layer interface,and the orientation is adjusted to complete the creation of the overall model.(3)According to the design data of horizontal and vertical sections,the three-dimensional modeling of urban rail transit lines is realized.Based on the three-dimensional coordinate data of the center line of the line,calculate the three-dimensional coordinates of each feature point of the line cross section,draw the line model among the cross sections by using the polygon function,give the corresponding texture,and complete the construction of the line three-dimensional model.(4)Research on the spatial analysis method of railway lines.Through the research of spatial query algorithm,buffer generation form and buffer analysis algorithm,the buffer analysis,collision detection and urban rail transit lines are combined to automatically judge the spatial relationship between the lines and surrounding objects,so as to provide designers with intuitive and real decision-making basis,which is helpful to improve the design efficiency and reduce the workload.