State about the Three-dimensional digitizers
Three-dimensional digitizers use sonic or electromagnetic transmissions to record positions. One electromagnet transmission method is similar to that used in the data glove. A coupling between the transmitter and receiver is used to compute the location of a stylus as it moves over the surface of an object. As the points are selected on a non-metallic object, a wireframe outline of the surface is displayed on the compute screen. Once the surface outline is constructed, it can be shaded with lighting effects to produce a realistic display of the object. Resolution of this system is from 0.8 mm to 0.08 mm, depending on the model.