摘要
空间透视仿射变换是在平行投影条件下的两空间场之间的变换。它具有平行投影的特性，其椭圆的仿射性质在解决某些二次曲面的截交线和相贯线的画法几何问题时，可避免作辅助椭圆、抛物线、双曲线等，从而大大简化了作图，是一种行之有效的方法。
perspective affinity shift is a transfer between fields of three dimentions in the condition of parallel projection. It has all properties of parallel projection. When some descriptive geometry problems about intersection of quadric surfaces and planes or quadric surfaces are dealt with,the use of these properties of perspective affinity of ellipse can avoid auxiliary views of ellipse, parabola, hyperbola etc. being drawn so that drawing process can be greatly simplified. Obviously the application of perspective affinity shift in descriptive geometry is an effective method.
关键词
透视仿射变换
平行投影
仿射性质
画法几何
Perspective affinity shift, Parallel projection, Perspective affinity
