摘要
提出了在流域三维虚拟仿真场景中绘制降雨时空分布等值线填充算法。依据边界点序列将得到的开等值线形成封闭多边形,采用改正辛普森面积法完成对所有等值线的同向。根据等值线的性质和射线求交法确定等值线的包含关系,并设计了等值线数据结构体,引入多叉树数据结构对等值线的拓扑关系进行组织。在此基础上,针对等值线的层数设计其对应的颜色条带,由等值线多叉树关系选择等值线填充颜色,从而完成等值线图的填充绘制,解决了三维仿真系统中任意比例尺、属性值间隔和边界情况下等值线的矢量快速填充的问题。最后将该算法运用到长江上游实测降雨过程的可视化研究中,验证了提出方法的实用性和可行性。
A contour filling algorithm for visualization of spatial and temporal distributions of rainfall in a three-dimensional watershed virtual environment is put forward in this paper.A closed curve is constructed by using watershed boundary points and generating open contours,and a modified Simpson-area method is used to make all the contours in the same direction.The inclusion relations of contours are determined by a ray intersection method and the contour features,and after designing the contour data structure a multi-tree data structure is introduced to construct topological relations of the contours.The color bands of contours are selected by the number of contour levels,and the choice of filling color depends on the multi-trees relationship of contours.This algorithm of rapid vector filling is effective in the cases of any scale,attribute values and boundary conditions in three-dimensional simulation system.Application to visualization of the rainfall process measured in the upper Yangtze reaches verifies the proposed algorithm.
出处
《水力发电学报》
EI
CSCD
北大核心
2011年第5期125-131,共7页
Journal of Hydroelectric Engineering
基金
国家自然科学基金创新研究群体基金项目(51021006)
"十一五"国家重点科技支撑计划课题(2008BAB29B08)
水利部公益性行业科研专项经费项目(200901031
201001024)
关键词
水资源
数字流域
水文数据
多叉树结构
等值线填充
虚拟仿真
可视化
water resources
digital river basin
hydrological data
multi-trees data structure
contour filling
virtual simulation
visualization
