In many computer graphics applications it is desirable to augment the virtual objects with high dynamic range images representing a real environment. In order to provide the illusion that the virtual objects are parts of the real scene, the illumination of the environment should be taken into account when the virtual objects are rendered. Proper calculation of the illumination from an environment map may be extremely expensive if we wish to account for occlusion, self shadowing and specular materials. In this paper we present a method that does all the calculations on a per-frame basis, and is already real-time on non-cutting-edge hardware.
HDRI, shadow, GPU, reflection.