This invention relates to a method and an apparatus for the three-dimensional digitization of objects with a 3D sensor, which comprises a projector and one or more cameras, in which a pattern is projected onto the object by means of the projector, and the pattern is detected with the one or more cameras. In accordance with the invention, the method and the apparatus are characterized in that at least three reference marks and/or a reference raster are projected onto the object with the 3D sensor and are detected with two or more external, calibrated digital cameras.