Research On The Three-Dimensional Modeling And Visualization Of Highway Roadbed

Under the background of the rapid development of highway construction in China,the design and management of highsway lines are facing great challenges.Due to the complexity and diversity of topography and landforms along most highways in China,the traditional two-dimensional graphic design can not directly evaluate the coordination between highway and its surrounding environment,and the design efficiency is low,which is easy to cause design defects,so it is difficult to meet the needs of highway construction.Three-dimensional visualization technology can overcome the limitations of traditional two-dimensional display,and can vividly and intuitively reflect the actual situation of highway construction under complex terrain.The construction and management of highway three-dimensional visualization based on actual scene has become a hot topic in current research.Focusing on the theoretical and technical problems involved in the three-dimensional modeling and visualization of highway roadbed,this paper studies the acquisition of three-dimensional terrain data and the establishment of terrain model,the parametric establishment of roadbed model,the fusion algorithm of roadbed model and terrain model,and realization of three-dimensional visualization system of highway.The main research contents and achievements are as follows:(1)Rapid establishment of three-dimensional terrain model of the highway.LocaSpace Viewer is used to quickly acquire terrain data and image data.Global Mapper is used to realize batch transformation of data coordinates in different coordinate systems.Finally,based on GIS platform,the transformed terrain data is generated into a three-dimensional scene cache,and the image data is directly loaded,thereby realizing the rapid construction of the highway three-dimensional digital terrain model.(2)Rapid establishment of highway roadbed’s three-dimensional model.This paper propose a parametric three-dimensional modeling method of highway roadbed based on Cesium.Through the secondary development of Cesium API,the rapid establishment of the roadbed cross-section,highway central line and three-dimensional models of highway roadbed are realized.JavaScript language is used to design the interface of roadbed standard cross-section parameter design,which is conducive to the inspection and modification of roadbed cross-section design scheme,and realizes the parametric design of roadbed standard cross-section.(3)Research on fusion algorithm of highway roadbed and terrain.An improved polygon clipping algorithm is proposed,which can effectively improve the speed of terrain clipping during the fusion of roadbed model and terrain model.Based on the secondary development of Cesium API,the fusion of roadbed model and terrain model is realized by using ClippingPlaneCollection and ClippingPlane function operation algorithm.(4)Realization and system development of three-dimensional visualization of highway.Taking the Yuqian highway roadbed proj ect as an example,the demonstration application of three-dimensional modeling method and fusion algorithm is carried out,and the three-dimensional visualization expression of highway roadbed is realized.According to Cesium and web technology,a three-dimensional visualization system of highway is developed with JavaScript as the main programming language.The functions of three-dimensional display and information query of terrain model and roadbed model are realized.