elbow knee interaction

In this teaching animation model, Master Chen Zhonghua shows how the elbow interacts with the knee in a negative circle.

In relation to the viewer’s eyes, the elbow point moves more horizontally from left to right then the other point points. The two knee points move more in line with the eye vision’s depth. Essentially, you should try to understand that the three points don’t change relationships. Only the three dimensional perspectives cause the flat one planed photos to appear to have the changes.