三维GIS中多分辨率纹理模型的研究  

Research on Multi-resolution Texture Model in Three-dimensional GIS

作　　者：杨必胜[1] 李清泉[2] 史文中[1] 

机构地区：[1]香港理工大学土地测量与地理资讯学系 [2]武汉大学空间信息与网络通信技术研发中心,武汉430079

出　　处：《中国图象图形学报（A辑）》2003年第3期328-333,共6页Journal of Image and Graphics

基　　金：国家自然科学基金项目 ( 6983 3 0 10 );数字香港的基础设施发展项目 ( 1.3 4.3 7.970 9);湖北省科技攻关项目 ( 2 0 0 1AA10 4A0 1) .

摘　　要：在三维地理信息系统 (GIS)中 ,影像数据作为模型表面的纹理特征 ,对弥补复杂模型的几何特性以及提高三维显示的效果具有十分重要的意义 .为了提高三维模型显示的速度和效果 ,以及为了降低纹理贴图时 ,影像的数据量 ,提出了一种与观察视点相关的动态多分辨纹理模型 ,并设计了相应的数据结构用于管理纹理数据 ,另外在讨论观察视点与纹理分辨率之间关系的基础上 ,开发了基于视点的确定纹理分辨率的算法 ,以用于交互三维显示时的纹理映射 ,最后给出了部分实验结果 .实验结果表明 ,多分辨率纹理模型的映射机制可以取得较好的可视化效果 .With the development of digital earth and cyber city, there is an increasing equipment on management and vitalization of integrated 3D model data and image data. How to improve the speed and visualization effect of three-dimesional(3D) model is a major research issue in 3D GIS. In order to improve the speed of 3D visualization, such as flying/walking through, many algorithms have been developed to reduce the data volume of 3D model, for instance, Level -of -Detail(Lod) algorithm. However, image data is also another important factor effecting the operation speed and reality of 3D model. Image data as the texture of surface of 3D model can enhance the reality of 3D model. For the reason that different graphic cards may have different restriction in the size of texture, the texture has to be managed very carefully. This paper proposes a new method to manage image data when a image is used as the texture for a 3D GIS environment. First, the data structure of multi-resolution texture model, which is developed to manage the large texture, is presented. Secondly, the algorithm that creates the multi-resolution texture model is developed, which is of vital importance for the texture mapping. Thirdly, the method of determining a proper texture resolution to map texture on the surface of 3D model based on viewer conditions is discussed. Finally, several experiments are illustrated.

关 键 词：三维GIS 三维地理信息系统 影像数据 分辨率 几何特性 纹理映射 

分 类 号：P208[天文地球—地图制图学与地理信息工程] TP391.41[天文地球—测绘科学与技术]