Camera tracking or matchmoving refers to the process of matching the position and angle of CGI (such as a spaceship or animated creature) to real footage shot with a film or video camera. This process can be accomplished manually, on a frame by frame basis. More common today is the use of automated matchmoving software based on computer vision techniques that can extract camera position and direction data over time from a piece of digitized footage with minimal user intervention. Done correctly, matchmoving allows the seamless compositing of CG and bluescreen elements into camera footage, even handheld camera footage.