摘要
根据同素性、从属性和等简比、等交比的特性,研究了透视对应中空间圆与投影椭圆之间的特性和变化规律,得出了同族变化定理、视角交比相关定理、等交比定理、平行二重直线对应线段的等简比定理、双心几何定理、透视椭圆定理,建立了中心投影和平行投影之间的几何对应关系,解决了透视椭圆的作图问题.
Based on the features of similar elements, subordination, brief ratio and equianharmonic cross ratio, this paper analyses the features and changing rules of spacial circle and perspective ellipse, and gets the similar family changing theorem, view cross ratio theorem, equianharmonic cross ratio theorem, corresponding section brief ratio theorem of two parallel lines, dual-center geometry theorem, perspective ellipse theorem. In addition, it builds up geometry relationship between centre projection and parallel projection and then solves the problems of drawing about perspective ellipse.
出处
《河南大学学报(自然科学版)》
CAS
北大核心
2006年第4期110-114,共5页
Journal of Henan University:Natural Science
基金
河南省科技攻关项目(20025700002)
关键词
中心投影
平行投影
透视椭圆
仿射变换
等交比性
双心定理
central projection
parallel projection
perspective ellipse
affine transformation
equianharmonic cross ratio feature
dual-center theorem