The Matrix is known for popularizing a visual effect known as bullet time, in which the heightened perception of certain characters is represented by allowing the action within a shot to progress in slow-motion while the camera's viewpoint appears to move through the scene at normal speed. The Wachowskis' approach to action scenes drew upon their admiration for Japanese animation and martial arts films, and the film's use of fight choreographers and wire fu techniques from Hong Kong action cinema influenced subsequent Hollywood action film productions.