Abstract: Cubemap environment mapping has been widely used in computer graphics applications,however,the cubemap samples the sphere unevenly.In this paper,we propose a novel six-face spherical map,isocube,that fully utilizes the cubemap hardware built in most GPUs.Unlike the cubemap,the proposed isocube samples the unit sphere and all samples span the same solid angle,hence it can achieve high-quality rendering results.Since the isocube has a small overhead in the mapping computation and it can exploit all built-in texturing operators tailored for the cubemap,isocube environment mapping can reach a very high frame rate.