Line drawing of complex objects not only includes scenograph, affine graph, linear projective graph and nonlinear projective graph, but also freehand sketch and graphics drew from images.

• 复杂物体的线图包括轴测图、透视图、仿射图、射影图和非线性投影图,也包括人徒手画的物体投影图和从图像中抽取的图形。