1. A method for performing computer-assisted orthopaedic surgery comprising the steps of: using a device to acquire first coordinate points on a surface of a first bone; using the device to acquire second coordinate points on a surface of a second bone that forms a joint with the first bone; producing and displaying a three-dimensional geometrical surface model of the first bone based at least initially on the acquired first coordinate points; producing and displaying a three-dimensional geometrical surface model of the second bone based at least initially on the acquired second coordinate points; moving the first and second bones relative to one another and detecting maximum amplitudes of rotation between the first and second bones; identifying a zone of impingement between the first and second bones on at least one of the bones; generating and displaying as a color map at least one surface of at least one bone model, the at least one surface being within the zone of impingement, the color map including different colors representing different depths of bone to be removed in order to achieve an increased range of motion between the two bones, the colors of the color map indicating a distance between a current bone surface and an objective bone surface for each point of the at least one surface, the objective bone surface being the bone surface that permits a target increased range of motion between the two bones to be achieved; using a tracked tool to remove bone in the zone of impingement based on real time information provided on the color map; and moving again the first and second bones relative to one another and detecting an increased amount of rotation between the first and second bones.