请您隔着玻璃窗观看窗外的花,把所见的形象在窗上画下来,这就是一幅透视图。画面(如玻璃窗),是一个铅垂面V(图1),在画面上作两根水平线:一根是通过视者眼睛的水平面与画面的交线HH,称作视平线:一根是过视者立足处的水平面与画面 Please observe the flowers outside the window through the glass window and draw the image you see on the window. This is a perspective view. The picture (such as a glass window) is a vertical plane V (Figure 1). Two horizontal lines are made on the screen: one is the line of intersection HH between the horizontal plane and the picture through the eyes of the viewer, which is called the eye level line: a It is the horizontal plane and the picture of the observer