1. A virtual coatings application system comprising: a display screen on which a virtual surface is displayed; an instrumented spray gun controller outputting one or more signals representing virtual spray gun data; a motion tracking system that tracks the position and orientation of the spray gun controller with respect to the virtual surface on the display screen; and a computer programmed with software which generates virtual spray pattern data in response to at least the virtual spray gun data and the position and the orientation data received from the tracking system; and wherein a virtual spray pattern image is displayed in real time on the display screen in accordance with the accumulation of virtual spray pattern data at each location on the virtual surface; and wherein the software comprises a paint model that outputs virtual spray pattern data to characterize the resulting pattern of the virtual spray in terms of spatter size and density on the virtual surface as a function of time in response to at least standoff distance and angular orientation of the spray gun controller relative to the virtual surface as well as virtual spray characteristic data representing settings for spray fan size, air pressure and paint flow rate.