An efficient modified Phong shading algorithm & its low-complexity realization

Abstract

A modified mixing shading algorithm is proposed, which costs much less operations than that of Phong shading algorithm. Based on the algorithm, a low-complexity shading engine is designed. The shading engine is performed in log space, using low-complexity logarithm and anti-log algorithms. The algorithms are combinations of interpolation algorithm using Taylor's expansion and table-lookup operations. This results in small table size, low complexity and high operation speed. Based on EDA tool simulations, the log-space engine can achieve a high clock rate of 450MHz and a fill rate up to 117.5M pixels/second, with total gate count of 12061.