BIM Lightweight Research And Application Based On Infrastructure Smart Service System

As the inevitable trend of the development of the construction industry in the future,BIM technology can visualize the whole life cycle management of engineering buildings and improve the efficiency of engineering construction.BIM 3D model of building engineering is often used in visual management of engineering projects.Shanghai institute of computing technology(hereinafter referred to as,SICT)entrusted by a university and in collaboration with the university to develop infrastructure intelligence service system.The system requires BIM 3D visual expression of engineering projects.In the construction of underground engineering BIM the model often has a large amount of data,occupies computer resources and is not convenient for non-designers to view the model in time.In order to better display and view the BIM model in underground engineering,this paper studies the lightweight BIM model on the basis of the real demand of infrastructure intelligent service system.And the lightweight research is applied to the infrastructure intelligent service system.This paper focuses on the research and realization of the lightweight display and interaction functions of 3D models in the data representation part.By inheriting the IExport Context class in Revit API,methods in the class are implemented to obtain the geometric information and material information of the model and serialize the output into JSON format files.The lightweight JSON file contains the key information of the model.Look for the technology needed to render JSON files in a browser,WebGL,and study how it renders.The scene,camera and renderer objects provided by the front-end development framework of Three.JS were used to construct and render the model.The translation,rotation and scaling of the model were realized by the track controller object,and the linkage between the model and engineering data was realized by the interaction functions provided by the ray projector object.This paper shows the realization effect of BIM lightweight model on the Web side,and tests the performance of BIM lightweight model.The test results show that the model data volume is reduced by about 70% after the lightweight technology,and the rendering on the Web side has high frame rate and good performance.At the same time,This paper applies BIM lightweight technology to the system and shows other main system functions.In the end,the research content of this paper is summarized,and the future research direction is prospected.