1. A method of providing a set of vertices representative of an outline of a portion of an object, the method comprising: a) casting a shadow of the object onto a detector at an angle to provide a shadow image on the detector; b) detecting at least one edge of the shadow image, the at least one edge of the shadow image and the angle forming a data pair; c) changing the angle and repeating the steps of casting and detecting until a plurality of data pairs is stored; and d) computing the set of vertices as a function of the data pairs.