【作者】 赵晓东；

【导师】 张军；

【作者基本信息】 辽宁工程技术大学 ， 地图制图学与地理信息工程， 2008， 硕士

【摘要】 三维模型是虚拟地理场景的基本要素,三维建模技术的研究一直伴随虚拟地理场景可视化技术发展的整个过程。本文基于VRML语言对虚拟地理场景建模的理论和方法作较深入的研究和探讨,并对几种不同的空间数据模型的构建分别进行研究。(1)本文利用VRML作为开发语言,进行地形建模研究。分别以DEM的两种组织方式GRID和TIN进行三维地形模型的建立。对地形纹理映射方法进行了研究,并提出了基于VRML的地形数据简化算法。(2)对建筑物的CSG建模方法进行了探讨。利用VRML语言实现了建筑物CSG建模,并提出了建筑物模型纹理映射合理有效的方法。(3)基于VRML语言实现了Billboard、十字交叉法和L系统的三维树木建模。Billboard、十字交叉法适用于大规模场景树木的显示,并可以提高显示速度。L系统树木模型逼真、自然。文章最后对所研究的工作进行了总结,并提出了进一步研究的内容。更多还原

【Abstract】 The three-dimensional model is the basic element of the virtual geographical scene. The research of modeling technology has been following the whole course of the visual technical development of the virtual geographical scene all the time. This paper makes deeper research and discussion to virtual geographical scene theory and method of modeling, and research respectively on the construction of several different kinds of space data models based on VRML language.(1) This paper studies to terrain modeling with VRML as the developing language, and builds the three-dimension terrain model in two kinds of organizations ways which are GRID and TIN of DEM separately, and research to terrain texture mapping. It advances a algorithm of VRML of simplify terrain data.(2) This paper discusses the method of CSG modeling. Building CSG modeling is built by VRML, the texture mapping of the building model is advanced in reason.(3) The paper realizes three-dimensional trees modeling of Billboard, Doubleboarding and L-System based on VRML. Billboard and Doubleboarding are applicable to the display of the extensive trees scene, and improve the speed of display. L-system trees model is lifelike, nature.At last, the paper summarizes conclusion of research, put forward the content further studying.更多还原