基于WebGL的轨道交通BIM轻量化应用方案

为了解决轨道交通建筑信息模型(BIM,Building Information Model)在Web端的渲染需求,提出了基于WebGL(Web Graphics Library)技术、JSON(JavaScript Object Notation)文件格式、FastDFS存储技术3者相结合的轨道交通BIM在Web端的轻量化应用方案。通过Revit的二次开发,提取Revit自有的BIM表面模型数据,将其使用JSON的方式存储;针对完整BIM对应的JSON格式文件较大的问题,提出了多个JSON格式文件代替一个JSON格式文件的存储方案;使用FastDFS文件服务器,将这些JSON格式文件存储;利用WebGL分级渲染FastDFS中的JSON格式文件。所提方案实现了轨道交通各专业BIM Web端显示。试验结果表明,BIM轻量化显示方案拥有非常好的通用性,对轨道交通的大模型兼容性好,保证了原始BIM数据精确,实现了各专业BIM的交互。

BIM lightweight application scheme of rail transit based on WebGL

In order to meet the requirements of Building Information Modeling(BIM) rendering on the Web side, this paper proposed a lightweight application scheme based on WebGL (Web Graphics Library) technology, JavaScript Object Notation (JSON) file format, and FastDFS storage technology. Through the secondary development of Revit, the BIM surface model data owned by Revit was extracted and stored in JSON format. Aiming at the problem of large JSON format file corresponding to the complete BIM model, a storage scheme of multiple JSON format files instead of one JSON format file was proposed; FastDFS file server was used to store these JSON format files; WebGL was applied to render hierarchically JSON format files in FastDFS. The scheme implemented the Web display of various professional BIM of rail transit. The test results show that this scheme has very good universality, good compatibility with the large model of rail transit, ensures the accuracy of the original BIM data, and implements the interaction of various professional BIM.