Computer display of curved surfaces

This research describes a method for producing shaped pictures of curved surfaces. It uses a small polygon approximation of the surface to solve efficiently the nidden parts detection, and then computes the shading on each polygon in such a way that visual discontinuities between adjacent polygons disappear, thus restoring the apparent smoothness of the surface and increasing greatly the realism of the pictures produced. The smooth shading technique described here has been used to produce a large variety of pictures of which several airplanes, a car, a human face and some mathematical surfaces are included to illustrate the effect of the method.