基于DEM数据的三维地形地类可视化研究

发布时间：2019-07-06 21:04

【摘要】：三维地形可视化是利用计算机图形学技术对地理信息中的地形数据进行可视化建模,并使用纹理、光照等增强现实技术,逼真地复现现实世界中的地形场景的技术。三维地形可视化是三维地理信息系统中的一个重要的研究课题,在国防建设、交通规划、游戏开发等领域都具有重要的应用价值。随着移动互联网的快速发展和移动设备的普及,移动设备正在改变人们访问互联网服务的方式。移动设备性能的快速提升,使基于移动设备的增强现实、虚拟现实的实现成为可能,基于移动平台的地形可视化研究及应用已成为新的发展趋势。本文针对大范围地形地类数据的三维可视化问题,研究了基于DEM数据的地形简化技术和地形多分辨率绘制技术,实现了地形地类在移动平台的三维的可视化；对土地利用现状图地类图斑的三维建模技术进行研究,提出一种快速构建地类三维模型的方法。论文主要工作如下：(1)设计了一种基于四叉树结构的地形简化算法。针对地形绘制效率低的问题,设计了基于四叉树结构的地形精简算法,有效地减少地形模型数据规模,提高了地形绘制效率。对地形的地形简化算法的节点评价方法进行研究,实现在地形精简的同时,保证了地形的可视化效果；对多分辨率模型裂隙修补技术进行研究,解决了地形渲染时空间连续性的问题。(2)提出一种基于外存的地形数据组织方法。结合数据压缩算法和地形简化算法,提出一种基于高度图金字塔的地形数据组织调度方法,对地形数据进行压缩,减少外存到内存数据调度量,并采用保持文件索引的方式,实现大地形文件的局部数据快速访问。(3)提出一种基于二维土地利用现状地类图斑和DEM数据构建地类三维模型的技术方法。研究纹理映射技术和矢量栅格化技术,通过二维矢量数据和三维地形模型数据融合的方式,实现了地类三维可视化。并进一步对地类图斑三维模型快速构建技术进行研究,提出了一种构建地类三维模型的技术方法,在现有数据基础上快速实现地类图斑三维模型构建。基于以上技术研究成果,结合工程软件开发技术,设计并开发Android三维地形地类可视化软件,实现了地形地类的三维可视化,经测试软件三维画面渲染流畅,交互效果良好。
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图片说明：图２－１体模型和面模型逡逑
[Abstract]:3D terrain visualization is a technology that uses computer graphics technology to visually model the terrain data in geographical information, and uses texture, lighting and other augmented reality techniques to reproduce the terrain scene in the real world realistically. 3D terrain visualization is an important research topic in 3D GIS, which has important application value in national defense construction, traffic planning, game development and other fields. With the rapid development of mobile Internet and the popularity of mobile devices, mobile devices are changing the way people access Internet services. With the rapid improvement of the performance of mobile devices, the realization of augmented reality and virtual reality based on mobile devices has become possible. The research and application of terrain visualization based on mobile platform has become a new development trend. In this paper, aiming at the problem of 3D visualization of large-scale terrain and ground data, the terrain simplification technology and terrain multi-resolution rendering technology based on DEM data are studied, and the 3D visualization of terrain class in mobile platform is realized, the 3D modeling technology of land use status map is studied, and a method of constructing land class 3D model quickly is put forward. The main work of this paper is as follows: (1) A terrain simplification algorithm based on quadtree structure is designed. In order to solve the problem of low efficiency of terrain rendering, a terrain simplification algorithm based on quadtree structure is designed, which can effectively reduce the data scale of terrain model and improve the efficiency of terrain rendering. The node evaluation method of terrain simplification algorithm is studied to ensure the visualization effect of terrain while the terrain is simplified. The crack repair technology of multi-resolution model is studied to solve the problem of spatial continuity in terrain rendering. (2) A terrain data organization method based on external memory is proposed. Combined with data compression algorithm and terrain simplification algorithm, a terrain data organization and scheduling method based on height map pyramid is proposed, which compresses terrain data, reduces the measurement of external memory data adjustment, and realizes fast access to local data of large terrain files by maintaining file index. (3) A technical method of constructing ground-like 3D model based on 2D land use status terrain spot and DEM data is proposed. Texture mapping technology and vector rasterization technology are studied. Three-dimensional visualization of ground class is realized by fusion of two-dimensional vector data and three-dimensional terrain model data. Furthermore, the rapid construction technology of land-like spot 3D model is studied, and a technical method of constructing ground-like 3D model is put forward, and the 3D model construction of ground-like spot is realized quickly on the basis of the existing data. Based on the above technical research results, combined with the engineering software development technology, the Android 3D terrain visualization software is designed and developed, and the 3D visualization of the terrain class is realized. The 3D picture rendering of the test software is smooth and the interaction effect is good.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P208;TP391.41

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