A system and a process for accurately aligning projection mapping systems using the assistance of camera sensors. The calibration process involves first projecting a modulated gray code image sequence that allows the calibration cameras to identify a dense set of image correspondences between the calibration cameras and the projectors. The calibration cameras are then aligned to the screen surface through the selection of key points or fiducials on the screen surface that are then identified in the camera images. Once the camera(s) are aligned to the screen surface, the image correspondences between the projectors and cameras are used to determine the alignment of the projectors to the screen surface.