three-dimensional perception in virtual reality settings

Many cues for three-dimensional sensation come from interaction among things. Key attributes of these connections are overlap, scale, and parallax. Objects that overlap on top of other parts are thought to be closer. Objects thought to be alike in actual size but appearing larger are thought to be closer and elements that grow in apparent size are seen to be moving nearer. Objects that move a more distance relative to other things when one's head moves are perceived as closer. Linked page PANO4YOU also covers these subjects.

The core of virtual reality is fooling the human body into perceiving things that are only artificially constructed. From this perspective, it is not surprising that one's body can react adversely, particularly when it gets contradictory signals from different senses and is not entirely fooled. With respect to vision, a limitation of today's VR image display systems is disharmony between eye focus (altering the lens of each eye at the perceived distance of the object viewed) and eye axial convergence (coordinating the angle of both eyes to cross focal lines at the apparent distance of the object). This problem is more acute for HMD systems in which pictures are displayed relatively close to one's eyes. Another problem is latency (a lag) between the kinetic motion impulses that the brain gets from the semicircular canals of the inner ear and the visual movement impulses that the brain receives from the eyes. When there is a lag in visual picture processing, then the body gets impulses of movement from kinetic senses in rapid-response but signals of movement from vision after lag time. Linked page Virtual Tours Brooklyn Park, Minnesota also delves into these concepts.

Linked page Gesture Recognition Systems also writes about some of this VR material.