（The game engine will keep track of everything in the world like such and such.
（The game engine will keep track of everything in the world like such and such.
这个游戏引擎将保留事物在世界中的轨迹。
（The game engine will keep track of everything in the world like such and such.
这个游戏引擎将保留事物在世界中的轨迹。