基于Erdas和DirectX平台的三维景观建模与应用

3D Landscape Modeling and Application Based on Erdas and DirectX Platform

三维GIS已成为当前地理信息系统研究的一个热点,而高分辨率卫星图像则是建设三维GIS的重要数据源。本文以IKONOS卫星图像立体像对为数据源,利用数字摄影测量的方法,开展目标地区的三维可视化信息提取,包括DEM生成、正射影像图制作,以及地面建筑物的三维信息和纹理图像的提取,然后,探讨应用ERDAS IMAGINE和3ds Max软件进行混合建模的技术方法,达到优势互补,完成地面建筑物的模型构建。最后,基于VC++6.0平台,结合DirectX软件开发包,综合利用多种技术自主开发构建目标地区的三维虚拟景观,实现地形地貌景观的浏览;进一步通过构建粒子系统对研究区冷却塔的烟雾效果进行模拟,通过加入生产环境和设施的各种影响因子模拟烟雾的变化,推理特定目标的生产活动状况,为项目的决策提供三维分析支持。

3D GIS has become a focus field of GIS study currently,and high-resolution satellite image is an important data resource for the 3D GIS construction.In this paper,based on the high-resolution IKONOS satellite stereo images,using the method to extract the 3D visualization information of the research area,including DEM extraction,orthophoto map making,3D information and texture of the ground building,the progress of the DEM extraction was analyzed and the errors of the DEM were corrected.A technical method that uses the ERDAS IMAGINE and 3ds Max software to carry on hybrid modeling was put forward.By complementing the advantages of two kinds of software,this method can accomplish the modeling work of the ground building better.Finally,based on the VC＋＋6.0 platform,combined with the DirectX SDK,the 3D visualization landscape was firstly constructed from two aspects,including the visualization of terrain and the loading of the ground feature models.In this process,in order to improve the operating speed,the Level of Detail algorithm and Mipmap technology were used to optimize the terrain visualization and the texture of the models.Further more,the diversification of the smog was simulated by constructing particle system and many factors of the environment and production facilities that can influence the movement of the smog were calculated and added.Through these work,the production activities of the special facility can be inferred,so it can provide support for the decision analysis.