The efficiency of a shading algorithm is critical to the performance of a computer image generation system(CIGS) because it must be operated on a million or more pixels per image. The efficiency problem is more critical in real-time CIGS like the interactive entertainment system(IES) which requires higher frame rate for the interactivity. It has been granted that Gouraud shading algorithm is most suitable for IES, although Gouraud shading can not completely eliminate the visibility of polygon edge. Phong shading is a well known algorithm for producing realistic shading, but it has not been used by IES because of the computational overhead. This thesis presents some new results on the comparison among various shading algorithms including two newly proposed shading algorithms, and guides users to find the most suitable algorithm for their IES applications. According to the result, when polygons are rather small, OverThrowMachine(OTM) Phong algorithm that uses the angular interpolation technique is the best for general IES applications because of its high speed and ability of restoring original smooth surfaces.
