| At present,the development of all walks of life has continuously deepened the demand for urban informatization.The development of the concept of Geographic Information System(GIS)has gradually shifted from the original model of object-oriented and component-oriented to service-oriented.The three-dimensional,hierarchical,refined,internal and external integration of the geographic information model,and the networking and service of the system technology are the future development direction of the GIS.The existing three-dimensional GIS system technology and modeling methods are difficult to meet the above requirements.With the continuous development of computer technology and the continuous deepening of GIS three-dimensional research,these problems will be solved.On the one hand,the development of HTML5 and WebGL technology solved the front-end rendering problem in the process of visualization of 3D geographic data.The advent of 3D Tiles and other 3D model layered slicing processing technology has loosened the restriction on the 3D model network transmission of large data volumes.On the other hand,the integration of BIM(Building Information Model)and 3D GIS technology will realize multi-scale application analysis of microscopic and macroscopic 3D regional scenes.It not only realizes the 3D modeling and application of large-scale macro outdoor scenes in the region.It also provides information on the interior space of the target building,so that the geographic information resources can be fully perceived,integrated,coordinated,and shared.This article focuses on the difficulties related to the integration of three-dimensional model web services technology and the integration research of 3DGIS and BIM,studies the three-dimensional model layered slice processing and related technologies of GIS and BIM model conversion,and builds a integrated network service platform of three-dimensional GIS and BIM based on Cesium..The main research content includes:1.Research WebGL technology,compare and select from various current three-dimensional map engines based on WebGL technology,construct the three-dimensional network service architecture according to the requirements of the engine.Plug-in issues and 3D model data sharing issues have been resolved from the aspect of network service and development.2.To explore the 3D model data format suitable for network transmission,study the 3D model layered slice processing technology,and solve the network transmission limitation and front-end rendering efficiency problems of the 3D model service.3.Compare the two technologies and applications of BIM and 3D GIS,and study the mapping methods of semantic information and geometric information based on the differences between the models.Converting the IFC model to a data format suitable for Cesium,and perform 3D model layered slice processing of the 3D model network service platform.4.Based on the three-dimensional GIS network service architecture studied in this paper,based on solving the problems of three-dimensional model network services and BIM and GIS data conversion,build a three-dimensional GIS network service platform that integrates BIM to verify the feasibility of the theory,lays the foundation for the integrated application of BIM and 3D GIS. |
