2D tracking provides the clues, but 3D calibration provides the solution. Calibrating, or solving, the camera is a fancy way of saying that we’re determining all of the camera’s attributes—position, rotation, focal length, and so forth. Now that we’ve given the matchmoving program some 2D information, it’s time to start solving.
Calibration can be one of the most difficult and frustrating parts of matchmoving to newcomers. Much of this is due to the “black box” nature of matchmoving software and the occasionally perplexing results. In this chapter, I’ll clarify some of the murkier aspects of 3D calibration and provide some tips for getting good results.