An efficient computer graphics tool for investigating the radiation patterns of antennas as functions of their design parameters is presented. Radiation patterns (or the magnitudes of field distributions) of antennas are treated as three-dimensional surfaces, since the magnitudes of the far-field distributions are functions of polar and azimuthal angles. Two-dimensional GKS (Graphics Kernel Systems) routines and a shading scheme based on the full-wave solution of light scattering from rough surfaces are used to provide a realistic view on the computer screen. Different types of radiation patterns and their characteristics are discussed. A review of antenna fundamentals is included. >