Matchmoving

Matchmove artists match computer-generated (CG) scenes with shots from live-action footage so the two can be convincingly combined.

They recreate live-action backgrounds (plates) on a computer in a way that mirrors the camera on the set in every way, including lens distortion. They do this by tracking the camera movements to make sure the real and virtual scenes appear from the same perspective.

Sometimes matchmove artists go to the film set to take measurements and put up tracking markers. Then they use these markers to track the camera movement and work out the relevant coordinates in the 3D scene. They do this using 3D tracking programs like Maya or 3DEqualizer.

Matchmove artists also do body and object tracking, using markers to recreate the movements of people, vehicles, or other objects in CG. The motion files created (camera, object, or body track) are then passed on to other departments via the VFX pipeline, so that, eventually, they can be seamlessly combined by the compositor.

Matchmove artists are highly accurate and meticulous in their work. It needs to be pixel-perfect, so they need an eye for detail. If the CG and live-action movements are not lining up perfectly, they have to find a way to fix this.