簡単な遠近法 Easy Explanation! The Basics of Two-point and Three-point Perspective [Environment Art Rudimentary]
There is a video commentary. This video explains the rudiments of background illustration, "2-point perspective" and "3-point perspective". Two-point perspective" is a diagram seen from an angle. It is called "two-point perspective" because there are two points of convergence (vanishing point: VP).