A new type of 3-D illusion with binocular viewing-pantomime effect

A new type of 3-D visual effect was found and called the pantomime (mime) effect, in which an illusory volumetrical transparent object is perceived via the visual stimuli of several objects arranged suitably and displayed stereoscopically. The illusory object perceived in the pantomime effect has a definite volume, not simply to be an illusory surface without thickness, and is transparent throughout the entire object. To interpret this phenomenon, a new framework for 3-D perception was proposed based on three types of sustaining cues: back, side, and front sustaining cues, which play different roles in perception of the volumetrical transparent illusory object. By using an illusory probe, we verified experimentally that the illusory object perceived in the pantomime effect is volumetrically transparent, and confirmed the essential role of side sustaining cues to volumetrical transparent object perception. We also studied this effect dynamically and found that the perception was more remarkably in dynamic situation than stationary situation. In addition, the illusory volumetrical transparent object could be perceived all the time as the structural shape changing continuously in the 3-D space. When the sustaining cues moved their positions and changed their orientations continuously between two different conditions, dynamic separation and fusion of the illusory object was observed and a hysteresis between them was recognized. Moreover, volumetrical color filling-up by sustaining cues was also perceived, and the volumetrical transparent illusory object´s color was determined by the contacting faces of the sustaining cues