The dynamics model of parachute-munition system is used to analyze the motion characters of submunition under the effect of wind gust, and the calculation model of projectivepoint is presented.
According to the nature of projective scale, it has solved the problem of drawing a cars perspective when perspective vanishing point is out of the drafting board.
文中利用射影几何中射线比的特殊性质，解决了透视灭点在图板外的透视图画法。
3
Single view metrology compute the 3d coordinate of a point based on the projective geometry's characteristic of cross-ratio invariability.