The method of drawing concave and convex sketches is as follows:

1. Use a pen to deepen the concave parts and draw some shadows on the convex parts.

2. Paint the concave areas darker and the convex areas lighter.

3. Contrast the relationship between light and dark. The dark place should not be completely black, but should have a sense of hierarchy. ?

If you want to draw a good sketch, a sense of three-dimensionality is indispensable. When we learn to draw, we basically focus on geometry at the beginning. This process is very boring and will cause many people to be unable to persist.

In fact, the practice of basic sketching is very important. It exercises our basic abilities such as observation ability, generalization ability, black and white and gray, and sense of space. The ultimate goal of practicing sketching is to enable us to draw realistically.

We can imagine that even a person who has never learned to draw will naturally feel awesome when he sees an exhibition in an art museum and sees paintings that express a good three-dimensional effect. To a large extent, three-dimensionality represents realism.

Representing this painting, the black and white, gray, structure and proportion are all handled properly. Many novices don't draw well because they don't handle the three-dimensional effect well. Many people understand this principle, but it is not easy to grasp it.

Many objects in reality are not simple geometries, but more complex than that. Take the human face as an example. The nose, cheekbones, eye sockets and ears are all complex objects that are difficult to draw directly. So at this time, you can summarize them into simple geometry, and it will be much easier to draw.