Virtual spectrophotometric measurements for biologically and physically-based rendering

The main topic of the paper is virtual spectrophotometers, virtual spectrophotometry and strategies for reducing the number of samples required to obtain asymptotically convergent measurements. A brief section on applications of virtual spectrophotometry is presented. This is followed by a careful formulation of virtual spectrophotometers. A virtual spectrophotometer, being a virtual device, is only described by its geometry.