Brief introduction of stick figure: Body structure is the most basic element of painting, and all kinds of objects have their own unique components, structural situations and proportional relationships. It is relatively simple to express two-dimensional plane structure with plane stick figures. However, the three-dimensional structure should be used to represent the image of the object, because it mainly shows one-sided graphics, so we should choose the angle and visual direction that can fully show the structural characteristics of the object when sketching, so that these characteristics can be prominently presented in the plane graphics.