One embodiment of the present invention sets forth an improved method for computing a cube map blur function. The method begins with a rendered cube map of the surrounding scene using conventional environment rendering techniques. The method then proceeds with three successive cylindrical blurs around each axis of a coordinate frame. The three blur operations accumulate results from each predecessor operation for the different pixels of the cube map, thereby generating a high quality cube map blur. One advantage of this technique is that a relatively low computational effort yields a blur function involving a relatively large number of source pixels for each resulting pixel. Therefore, the resulting cube map can be computed in real-time and is suitable for use in a wide range of lighting effects.