(For example, all students have taken the train. When they took the train, they met their own train, which apparently stopped, but the trains on the surrounding tracks are moving backward. They will have an illusion that their train is moving forward, hehe. The map principle of flying shooting games is exactly the same as this one. The player is controlling the position of the aircraft flying on the screen. The background image rolls back all the time and then gives the player the illusion that the aircraft under his control is flying forward. As shown in the figure below, two map images replace the roll on the back of the screen, which will give the player the illusion of moving forward. This document includes the following annexes:)