Research On Fast Construction Method Of 3D Geographic Scene Integrating GIS-BIM

In this paper,a fast method of building three-dimensional geographic scene integrating GIS-BIM data is studied.Smart city has gradually developed into a new type of smart city.Therefore,it is necessary to enhance the integration of urban space expression both indoor and outdoor,above and below the ground,so as to realize the fine management of the city.With BIM(Building Information Model)becoming an important data source of building internal structure,it is an important research content to integrate BIM with GIS(Geographic Information System)data and establish three-dimensional geographic scene.The integration of the two is conducive to the integration of macro and micro scenarios.Because BIM data has the characteristics of large amount of data and complex structure,in order to achieve real-time rendering of three-dimensional geographic scenes in the network environment,it is necessary to deepen the research on data structure and visualization performance.In order to solve the above problems,this paper summarizes the main methods of multi-scale spatial data organization and accelerated scheduling of three-dimensional geographic scene data.By designing data organization model,data processing method and visualization strategy,a fast construction method of three-dimensional geographic scene integrating GIS-BIM data is realized.This method organizes the data of GIS-BIM efficiently,and realizes the integration of GIS-BIM in the data rendering layer and seamless links between scales through the transfer format of graph function library.In addition,this method utilizes data scheduling technologies such as visual domain culling,view-based LOD adaptive selection,data caching and so on to quickly build three-dimensional geographic scenes.In this paper,the GIS-BIM data are unified in three-dimensional geographic scenes of various topics to provide services for the safety monitoring and management of hydraulic structures,disaster emergency,virtual reality,public safety,new intelligent cities and other fields.In order to realize this method,this paper independently designs and implements a three-dimensional geographic scene display system integrated by GIS-BIM.The main research contents and achievements are summarized as follows:(1)A mixed data structure compatible with GIS-BIM data is designed.Taking the LOD structure of detail level as the core,glTF is proposed as the intermediate format to realize the conversion of GIS-BIM data to glTF format.Through lightweight GIS-BIM data,it provides data support for rapid scene construction.(2)A data scheduling strategy for rapid construction of three-dimensional geographic scenes is designed.This method uses viewpoint-related tile data dynamic scheduling,caching technology and visual domain culling technology to formulate three-dimensional geographic scene data scheduling rules for GIS-BIM data,reduce data transmission and browser-side rendering in the network environment,enhance real-time rendering efficiency of large-scale 3D scene integrated with GIS-BIM data,and lay the foundation for deep application of 3D geographic scene.(3)By developing a three-dimensional geographic scene display system integrating GIS-BIM data,it is verified that the proposed method of organizing and scheduling GIS-BIM data can support the rapid construction of three-dimensional geographic scene.In addition,the system designed in this paper has been applied in practical projects,focusing on the service of hydraulic building safety monitoring,police safety information system and other projects.