NORMALIZATION OF VECTORS ASSOCIATED WITH DISPLAY PIXELS OF COMPUTER GENERATED IMAGES

A computer graphics method of and apparatus for normalizing vector-based terms for a plurality of display pixels associated with a polygon representing a surface of an object being imaged, the vector-based terms being determined from predetermined vectors at vertices of the polygon. The square (.eta.) of the magnitude of a vector associated with each vector-based term is determined for each display pixel from the predetermined vectors at the vertices of the polygon. The quantity 1/.sqroot..eta. is approximated for each vector-based term using a series expansion employing .eta., and each vector based term is multiplied by the corresponding approximation of 1/.sqroot..eta. to produce a normalized vector-based term for each display pixel.