Perceptual Illumination Components: A new approach to

efficient, high quality global illumination rendering

Stokes, W., Ferwerda, J.A. Walter, B.J. and Greenberg, D.P.

In this paper we introduce a new perceptual metric for efficient,

high quality, global illumination rendering. The metric is based on a

rendering-by-components framework in which the direct, and indirect

diffuse, glossy, and specular light transport paths are separately

computed and then composited to produce an image. The metric

predicts the perceptual importances of the computationally expensive

indirect illumination components with respect to image quality.

To develop the metric we conducted a series of psychophysical

experiments in which we measured and modeled the perceptual importances

of the components. An important property of this new

metric is that it predicts component importances from inexpensive

estimates of the reflectance properties of a scene, and therefore adds

negligible overhead to the rendering process. This perceptual metric

should enable the development of an important new class of ef-

ficient global-illumination rendering systems that can intelligently

allocate limited computational resources, to provide high quality

images at interactive rates.