1. Draw a square first, and cut out the inscribed regular octagon with a straight line (you can find the horizontal and vertical central axes).
2. Cut out the inscribed regular hexagon (short straight line can be used). The more trimmings, the closer the pattern is to a circle.
3. Because of the light, it is produced on the volume of the object. Width and width according to the brightness and the shape of the object, draw the dividing line between light and dark, and form a three-dimensional effect by tiling.
Fourth, according to the dividing line between light and shade, enrich the gray and white.
5. Carefully analyze the differences, combine the background to make it three-dimensional, and use and deeply contrast the dark, gray, bright and surface to draw a three-dimensional and layered feeling.