A hardware cost minimized fast Phong shader

One of the most successful algorithms that bring realism to the world of three-dimensional (3-D) image generation is Phong shading. With the continuous improvement in VLSI technology and the demand for higher realism, this algorithm is amenable to the commercially available hardware implementation for real-time rendering in 3-D graphics. Taylor series approximation is appropriate for the hardware implementation of fast Phong shading. However, in this method, the exponentiation of the cosine term requires a very large ROM table. This paper describes the minimization of this overhead in terms of hardware size by proposing an adaptive-compressed nonuniform quantization method. With this method, the ROM table is reduced to 1/64th of the size required for a uniform quantization method while the picture quality is maintained. Due to the reduced ROM table size, the size of the total hardware required for fast Phong shading is minimized to 1/56th of the original size.