Although it should have been a closed set, there were actually many people present, moving the walls of the set in order to allow full movement of the camera around the actors.
虽然这本应是封闭式的片场，但实际上有很多人在场，片场的多面墙壁都进行了移动，以便摄影机可以自由地围绕演员进行拍摄。