Gap Affordance Judgments in Mixed Reality: Testing the Role of Display Weight and Field of View

Abstract

Measures of perceived affordances—judgments of action capabilities—are an objective way to assess whether users perceive mediated environments similarly to the real world. Previous studies suggest that judgments of stepping over a virtual gap using augmented reality (AR) are underestimated relative to judgments of real-world gaps, which are generally overestimated. Across three experiments, we investigated whether two factors associated with AR devices contributed to the observed underestimation: weight and field of view (FOV). In the first experiment, observers judged whether they could step over virtual gaps while wearing the HoloLens (virtual gaps) or not (real-world gaps). The second experiment tested whether weight contributes to underestimation of perceived affordances by having participants wear the HoloLens during judgments of both virtual and real gaps. We replicated the effect of underestimation of step capabilities in AR as compared to the real world in both Experiments 1 and 2. The third experiment tested whether FOV influenced judgments by simulating a narrow (similar to the HoloLens) FOV in virtual reality (VR). Judgments made with a reduced FOV were compared to judgments made with the wider FOV of the HTC Vive Pro. The results showed relative underestimation of judgments of stepping over gaps in narrow vs. wide FOV VR. Taken together, the results suggest that there is little influence of weight of the HoloLens on perceived affordances for stepping, but that the reduced FOV of the HoloLens may contribute to the underestimation of stepping affordances observed in AR.

Familiar size affects perception differently in virtual reality and the real world

“…As reviewed elsewhere [ 83 ], current VR displays do not perfectly match the visual information provided in natural environments for many reasons. Our results are not easily explained by a limited field of view [ 16 , 19 ] because the objects were in central vision, surrounded by a black void nor display latencies [ 84 ] (because head movements and motion parallax were limited). However, other limitations of VR could have plausibly affected our results.…”

“…The XR-1 focal plane is at 1 m (John O'Neill, Varjo technical support, 2022, personal communication). Although headset weight and front-heaviness do not appear to account for perceptual distortions in mixed reality [ 19 ], one additional difference between the two studies was that the Varjo headset, which was used with a counterweight to reduce front-heaviness (1300 g), was heavier that the Oculus (470 g).…”

“…Participants viewed the six virtual sports balls in VR using a Varjo XR-1 HMD. The Varjo HMD provides automatic adjustment for participant IPD (adjustment range 61-73 mm; supported range 59-75 mm) and uses foveated rendering to provide a resolution of 60 pixels degree −1 in central vision (1920 × 1080 resolution, 60-Hz refresh rate) and 16.5 pixels degree −1 in the periphery (1440 × 1600 screen, 87°× Although headset weight and front-heaviness do not appear to account for perceptual distortions in mixed reality [19], one additional difference between the two studies was that the Varjo headset, which was used with a counterweight to reduce front-heaviness (1300 g), was heavier that the Oculus (470 g). Each familiar large object was shown at its regulation size (volleyball, 21 cm, soccer ball 22 cm and basketball 24 cm) or at the average size of the familiar small objects (5.8 cm).…”

“…[8][9][10][11][12][13][14]). The cause of geometric distortions in VR is unclear and cannot be fully attributed to reduced field of view [15][16][17], the physical weight of HMDs [18,19], or graphics quality [20]. Experiments in Cave Automatic Virtual Environments have demonstrated that size perception depends upon multiple sources of information.…”

Advanced liquid crystal devices for augmented reality and virtual reality displays: principles and applications

“…Such a projection process demands the display panel to have a much higher resolution density than that of a direct-view display. The visual acuity of the human vision system is 1 arcmin 46 , then a 6 K resolution display is typically required to support a 100° FoV VR headset 47 . To achieve a compact form factor, such a 6 K × 6 K resolution needs to be assembled on a 2–3-inch panel, resulting in a 2000 PPI of the microdisplay panel.…”