Perceived Size in Virtual Environments: The Role of Pictorial Depth Cues

Abstract

Virtual two-dimensional environments attempt to represent accurate spatial information by employing redundant sources of information (e.g., linear perspective, foreshortening, aspect ratio, texture gradient, interposition, and height relative to the horizon). Under certain conditions, size constancy maintains in these displays. However, more understanding is needed about the differential effects of these cues and how they combine to support size constancy. Experiment I explored the role of linear perspective and foreshortening on size constancy by having observers make height and width judgments of objects on a receding flat “perspective” surface in which one, both, or neither cue was present. Experiment II explored the role of several different combinations of pictorial depth cues on size constancy. Overall, height judgments were more accurate than width judgments. Foreshortening was identified as an especially important cue for maintaining size constancy. However, increasing the number of pictorial depth cues present did not necessarily correspond with more veridical size perception.