摘要
三维地形是虚拟自然环境中不可缺少的因素 ,也是虚拟仿真领域中视景系统的重要组成部分 .该文将地形生成技术概括为基于真实地形数据的地形生成技术、基于分形技术的地景仿真技术、基于数据拟合的地形仿真技术等三大类 ,并分别介绍了这三类方法的相关理论和生成技术 ,还分析了各自的发展趋势 .其中在基于真实数据的地形生成方面 ,按照离散 L OD模型、连续 L OD模型、多分辨率模型的发展顺序 ,重点介绍了地形实时显示技术中数据简化方面的典型算法 .
Three dimensional terrain is one of important factors of the natural scenes in virtual environment. It is also a significant composition of view system in virtual simulation field. The paper presents terrain generation techniques based on real terrain datasets, and terrain simulation techniques that are based on fractal geometry as well as data fitting methods respectively. Among the terrain generation techniques based on real terrain datasets, emphasis is laid on the real time display of terrain and some typical data simplification algorithms are introduced according to their appearing time: discrete LOD, continuous LOD, and multiresolution model. Related conceptions and features of those algorithms are also discussed. In terrain simulation techniques based on fractal geometry, the paper gives an overview of several fractal modeling methods, and then makes a further discussion on two kinds of typical recursive subdivision plans of midpoint displacement that is the most practical approach in some applications. In data fitting techniques, plane fitting, curved surface fitting, and real terrain simulation according to some given topographic parameters are introduced. Finally, the development tendencies of all these techniques are discussed.
出处
《中国图象图形学报（A辑）》
CSCD
2000年第4期269-276,共8页
Journal of Image and Graphics
基金
国家 8 63计划 3 0 6主题
航空科学基金项目
航空高等院校自选科研课题
关键词
三维地形
虚拟环境
实时显示
自然景物建模
Three dimensional terrain, Virtual environment, DTM, LOD, Real\|time display, Fractal geometry, Data fitting
