MIP-Map Level Selection for Texture Mapping

Texture mapping is a fundamental feature of computer graphics image generation. In current PC based acceleration hardware, MIP-mapping with bilinear and trilinear filtering are commonly used filtering techniques for reducing spatial aliasing artifacts. The effectiveness of these techniques in reducing image aliasing at the expense of blurring is dependent upon the MIP-map level selection and the associated calculation of screen space to texture space pixel scaling. This paper describes an investigation of practical methods for per pixel and per primitive level of detail calculation. This investigation was carried out as part of the design work for a screen space rasterization ASIC. The implementations of several algorithms of comparable visual quality are discussed and a comparison is provided in terms of per primitive and per pixel computational costs. Index Terms — Texture mapping, filtering, MIP-map, minification, level of detail, rasterization, interpolation.