Differences in Three Vection Indices (Latency, Duration, and Magnitude) Induced by "Camera-Moving" and "Object-Moving" in a Virtual Computer Graphics World, Despite Similarity in the Retinal Images.

To create a self-motion (vection) situation in three-dimensional computer graphics (CG), there are mainly two ways: moving a camera toward an object ("camera moving") or by moving the object and its surrounding environment toward the camera ("object moving"). As both methods vary considerably in the amount of computer calculations involved in generating CG, knowing how each method affects self-motion perception should be important to CG-creators and psychologists. Here, we simulated self-motion in a virtual three-dimensional CG-world, without stereoscopic disparity, which correctly reflected the lighting and glare. Self-motion was induced by "camera moving" or by "object moving," which in the present experiments was done by moving a tunnel surrounding the camera toward the camera. This produced two retinal images that were virtually identical in Experiment 1 and very similar in Experiments 2 and 3. The stimuli were presented on a large plasma display to 15 naive participants and induced substantial vection. Three experiments comparing vection strength between the two methods found weak but significant differences. The results suggest that when creating CG visual experiences, "camera-moving" induces stronger vection.