A plausible lightweight dirt model for application in real-time 3D environments

Dirt is an important, if unattractive, feature of our real world, the presence of which provides key subliminal cues that enhance understanding of many factors including age, history, economic and social status. In addition, the accumulation of dirt may also aid in the perception of fine detail, on complex surfaces, by highlighting fine features. Because dirt is such an important factor in the manner in which we perceive the real world, its inclusion in 3D virtual environments should significantly increase the sense of presence a user experiences by creating a more plausible impression of the real world environment. Most traditional approaches for incorporating dirt into 3D environments rely on either highly complex, but accurate, simulations, or depend on artistic skill. This research seeks to identify an alternative approach, grounded in human perception, which evaluates simplified approximations of dirt aggregation with the aim of identifying an approximate model that presents a plausible representation of dirt. This paper describes the process by which such an approximation has been identified and evaluated, and presents surprising results as to the level of complexity such a model requires to be viable.