Size-Constancy in the CAVE

Abstract

The use of virtual environments (VE) for many research and commercial purposes relies on its ability to generate environments that faithfully reproduce the physical world. However, due to its limitations the VE can have a number of flaws that adversely affect its use and believability. One of the more important aspects of this problem is whether the size of an object in the VE is perceived as it would be in the physical world. One of the fundamental phenomena for correct size is sizeconstancy, that is, an object is perceived to be the same size regardless of its distance from the observer. This is in spite of the fact that the retinal size of the object shrinks with increasing distance from the observer. We examined sizeconstancy in the CAVE and found that size-constancy is a strong and dominant perception in our subject population when the test object is accompanied by surrounding environmental objects. Furthermore, size-constancy changes to a visual angle performance (i.e., object size changed with distance from the subject) when these surrounding objects are removed from the scene. As previously described for the physical world, our results suggest that it is necessary to provide surrounding objects to aid in the determination of an object's depth and to elicit size-constancy in VE. These results are discussed regarding their implications for viewing objects in projection-based VE and the environments that play a role in the perception of object size in the CAVE.

Perceptions of an automotive load space in a virtual environment

“…Previous research has indicated that further studies of spatial understanding of VR are required in new contexts (Wartenberg and Wiborg, 2003) and that the results are specific to the environment and task conditions (Waller, 1999;Wartenberg and Wiborg, 2003;Lin et al, 2014;Kenyon et al, 2007). Overall, our results showed that perception of space was not significantly different between the virtual (CAVE) and real vehicle for subjective ratings of distance and volume.…”

The use of virtual reality and physical tools in the development and validation of ease of entry and exit in passenger vehicles

“…Murgia and Sharkey (2009) found that the underestimation of depth was less in a rich virtual environment with textured background surfaces. Similarly, Kenyon et al (2007) found improvements in size constancy (the ability to perceive objects of the same size at a variety of distances) in richer virtual environments with surrounding objects providing depth cues. Hu et al (2000) found improvements from the use of shadows and object inter-reflections in participants' ability to judge imminent contact between virtual objects.…”

“…For example, the effect of graphics quality on distance perception has been recognised as an open area requiring more research (Kenyon et al, 2007;Renner et al, 2013). Renner et al (2013) emphasise the importance of a virtual environment with a ground texture, as the "compression" of texture at further distances can be an important cue (Renner et al, 2013).…”

A perceptual calibration method to ameliorate the phenomenon of non-size-constancy in hetereogeneous VR displays

“…In HMDs, objects tend to increase its apparent size whereas, in LIPDs, similar asymmetric effects are produced. These effects were first reported by Kenyon et al (2007) [7] using a CAVE system. They used a perceptual matching task to measure indirectly the perception of distance, requesting subjects to estimate the apparent size of a virtual object located at different distances over a virtual table, as it is shown in Figure 1.…”

“…Also, when the complexity of the scene increases, subjects make better judgments based on surrounding objects ( [7], [16]). These characteristics make it suitable as a method to assess distance perception indirectly using perceptual matching approaches ( [16], [4]).…”