1. A non-contact digital contour generator for generating the X, Y and Z coordinates of the surface of a three-dimensional model comprising: an adjustably mounted light source for successively providing contour lines about said model at different levels thereof, the movement of said light source being measured to provide a first of said coordinates; a camera having an object plane and an image plane, said camera having its optical axis disposed perpendicular to the plane of the contour line and adjustably mounted such that its object plane is maintained in the plane of the contour line as the latter is changed to a different level so as to focus the image of the contour line on said image plane; and scanning means including photosensitive means located in the image plane of said camera for scanning the successive images of the contour lines focussed thereon to provide the second and third of said coordinates.