Match Moving

In cinematography, match moving is a visual-effects technique that allows the insertion of computer graphics into live-action footage with correct position, scale, orientation, and motion relative to the photographed objects in the shot. The term is used loosely to refer to several different ways of extracting motion information from a motion picture, particularly camera movement. Match moving is related torotoscoping and photogrammetry. It is sometimes referred to as motion tracking.

Match moving is sometimes confused with motion capture, which is a hardware technology for recording the motion of objects, often human actors, in a controlled environment using special cameras and sensors. It is also distinct from motion control photography which uses a robotic arm to execute multiple identical camera moves. Match moving, by contrast, is typically a software-based technology, applied after the fact to normal footage recorded in uncontrolled environments with an ordinary camera.

Match moving is primarily used to track the movement of a camera through a shot so that an identical virtual camera move can be reproduced in a 3D animation program. When new animated elements are composited back into the original live-action shot, they will appear in perfectly-matched perspective and therefore appear seamless.

As it is mostly software-based, match moving has become increasingly affordable as the cost of computer power has declined; it is now an established visual-effects tool and is even used in live television broadcasts as part of providing effects such as the virtual yellow-down-line in American football.