Depth and distance perception in a curved large screen virtual reality installation

Abstract

The study of humans' perceptual experiences in Virtual Environments (VEs) plays an essential role in Virtual Reality (VR) research field. In particular, in the last years several researches were proposed regarding the problem if depth and distance are perceived in VEs as they are perceived in Real Environments (REs), and possibily what conditions affect a non correct estimation by the observers. This problem is very relevant in order to use VR as a supporting tool in fields where correct perception of space and distance is vital, like e.g. the training of personnel in dangerous environments. Many theories have been suggested regarding the combination and relation between different depth cues; unfortunately, no conclusive answer has been proposed. However, a common conclusion between all the experiments is that observers underestimate long distances in VEs. Although the causes of this phenomenon are still uncertain, it's reasonable to speculate that something must differ in the way distance and depth are extracted and processed between the RE and the VE. Moreover, it is worth noting that very few works considered VR installations with large projection screen, covering a large field of view (FOV) in the observation process. In this paper, we aim at investigating depth perception in the Virtual Theater of the University of Milan, a VR installation characterized by a large semicylindrical screen that covers 120° of horizontal FOV. For its characteristics, the Virtual Theater represents an interesting and never considered test ground for psychophysical experiments regarding deph perception in VEs. We will present some preliminar perceptual matching experiments regarding the effect of shadows and reflections in the estimation of distances in VEs, and we will discuss the obtained results.