School of Civil & Building in Tongji University is the most famous research institution in the worldwide way. Smart3D Media Lab, as another leadership of lightweight Web3D key technology in Tongji University, aims at real time interactive visualization of Big BIM models over Internet. A hybrid team of Smart-Building and SmartWeb3D in Tongji developed a Pervasively Collaborative Smart3D BIM Visualization Platform on Mobile Internet for building planners, designers, constructors, investors, supervisors, end-users by accessing mobile Web Browsers anytime and anywhere, that will bring BIM with radical innovations by integrating “Internet+”, “BIM+” and “VR+”.
In this project, we present a Web3D-based lightweight solution for real time visualization of big BIM data scene, on considering its redundancy, semantics, parameterization but the limited resources of the network bandwidth and web browsers.
Firstly, taking industry foundation classes (IFC) as the input data format, we conduct a lightweight preprocess on raw BIM data via semantics analysis, reused object removal and geometry data parameterizing.
Secondly, we extract the space structure from the raw building for visibility culling and construct a scene index based on the sparse voxelization.
Thirdly, we integrate the above together in a progressive management strategy to update the scene data in real time.
The final system demonstrates: (a) with the semantics information, our method enables to significantly reduce the redundancies of the raw BIM big data; (b) the scene index supports data access and facilitates the indoor/outdoor visibility culling efficiently; (c) our management strategy does not only integrate our prototype system but also introduce a progressive management idea to improve the efficiency of resource consumption.