基于Cesium的WebGIS流域虚拟场景搭建

Cesium-based construction of WebGIS watershed virtual scene

为了在Web端更直观展示三维数字流域可视化信息,结合广泛运用于实际工程项目的倾斜摄影技术、BIM模型、WebGL可视化等前沿热点技术,介绍了基于地图引擎Cesium搭建流域虚拟可视化场景环境的方法。Cesium是一个基于WebGL的开源三维地图引擎,它解决了传统插件式Web三维虚拟场景兼容性差的问题,实现跨平台三维流域信息Web端流畅加载。采用Java Script与WebGL为开发语言,基于B/S架构,采用缓存下载、切片技术实现地形与影像的集成加载;采用3DMAX、Revit、Super Map iDesktop等工具实现倾斜摄影模型与精细模型的转换与集成加载;采用nginx反向代理,Ajax异步调用技术实现水情信息的集成可视化;最后达到了流域多种信息集成显示的效果,对基于Web的流域仿真具有较好的参考价值。为流域模拟仿真WebGIS平台探索了快速智能的搭建方案。

In order to more intuitively exhibit the visualization information of 3D digital watershed at Web end,the method for constructing virtual visual scene environment of watershed with the map engine—Cesium is described herein in combination with the hot-spot and frontier techniques,i. e. oblique photography technology,BIM model,WebGL,etc.,which are widely applied to the actual engineering projects concerned. Cesium is a WebGL-based open source 3D map engine,which solves the problem of poor compatibility of the conventional plug-in Web 3D virtual scene,and then realizes the smooth load of the cross-platform 3D watershed information at Web end. Taking Java Script and WebGL as the developing languages,the integrated load of both terrain and image is achieved with the techniques of cache-download and slicing on the basis of B/S structure,while the conversion and integrated load of the oblique photographic model and the fine model are realized with the tools of 3D MAX,Revit,Super Map i Desktop,etc. and the integrated visualization of water regime information is realized with the techniques of nginx reverse-proxy and Ajax asynchronous call,finally,the integrated display of various information of watershed is achieved,which not only has a better referential value for the Web-based simulation of watershed,but also explores a quick and intelligent construction scheme for the WebGIS platform for watershed simulation.