Perceptual scaling of visual and inertial cues: effects of field of view, image size, depth cues, and degree of freedom.

In the field of motion-based simulation, it was found that a visual amplitude equal to the inertial amplitude does not always provide the best perceived match between visual and inertial motion. This result is thought to be caused by the "quality" of the motion cues delivered by the simulator motion and visual systems. This paper studies how different visual characteristics, like field of view (FoV) and size and depth cues, influence the scaling between visual and inertial motion in a simulation environment. Subjects were exposed to simulator visuals with different fields of view and different visual scenes and were asked to vary the visual amplitude until it matched the perceived inertial amplitude. This was done for motion profiles in surge, sway, and yaw. Results showed that the subjective visual amplitude was significantly affected by the FoV, visual scene, and degree-of-freedom. When the FoV and visual scene were closer to what one expects in the real world, the scaling between the visual and inertial cues was closer to one. For yaw motion, the subjective visual amplitudes were approximately the same as the real inertial amplitudes, whereas for sway and especially surge, the subjective visual amplitudes were higher than the inertial amplitudes. This study demonstrated that visual characteristics affect the scaling between visual and inertial motion which leads to the hypothesis that this scaling may be a good metric to quantify the effect of different visual properties in motion-based simulation.