J. Edward Swan II’s research while affiliated with Mississippi State University and other places

Virtual Reality (VR) technology has advanced to include eye-tracking, allowing novel research, such as investigating how our visual system coordinates eye movements with changes in perceptual depth. The purpose of this study was to examine whether eye tracking could track perceptual depth changes during a visual discrimination task. We derived two depth-dependent variables from eye tracker data: eye vergence angle (EVA) and interpupillary distance (IPD). As hypothesized, our results revealed that shifting gaze from near-to-far depth significantly decreased EVA and increased IPD, while the opposite pattern was observed while shifting from far-to-near. Importantly, the amount of change in these variables tracked closely with relative changes in perceptual depth, and supported the hypothesis that eye tracker data may be used to infer real-time changes in perceptual depth in VR. Our method could be used as a new tool to adaptively render information based on depth and improve the VR user experience.

An important research question in optical see-through (OST) augmented reality (AR) is, how accurately and precisely can a virtual object’s real world location be perceived? Previously, a method was developed to measure the perceived three-dimensional location of virtual objects in OST AR. In this research, a replication study is reported, which examined whether the perceived location of virtual objects are biased in the direction of the dominant eye. The successful replication analysis suggests that perceptual accuracy is not biased in the direction of the dominant eye. Compared to the previous study’s findings, overall perceptual accuracy increased, and precision was similar.

Figure 1: Experimental methodology. The triangulation by walking task (a) is performed for each condition: opaque wall (b), virtual window (c), and virtual window and background (d). ABSTRACT Accurate and usable x-ray vision is a significant goal in augmented reality (AR) development. X-ray vision, or the ability to comprehend location and object information when it is presented through an opaque barrier, needs to successfully convey scene information to be a viable use case for AR. Further, this investigation should be performed in an ecologically valid context in order to best test x-ray vision. This research seeks to experimentally evaluate the perceived object location of stimuli presented with x-ray vision, as compared to real-world perceived object location through a window, at action space distances of 1.5 to 15 meters.

In optical see-through augmented reality (AR), information is often distributed between real and virtual contexts, and often appears at different distances from the user. To integrate information, users must repeatedly switch context and change focal distance. If the user's task is conducted under time pressure, they may attempt to integrate information while their eye is still changing focal distance, a phenomenon we term transient focal blur . Previously, Gabbard, Mehra, and Swan (2018) examined these issues, using a text-based visual search task on a one-eye optical see-through AR display. This paper reports an experiment that partially replicates and extends this task on a custom-built AR Haploscope. The experiment examined the effects of context switching, focal switching distance, binocular and monocular viewing, and transient focal blur on task performance and eye fatigue. Context switching increased eye fatigue but did not decrease performance. Increasing focal switching distance increased eye fatigue and decreased performance. Monocular viewing also increased eye fatigue and decreased performance. The transient focal blur effect resulted in additional performance decrements, and is an addition to knowledge about AR user interface design issues.

For optical see-through augmented reality (AR), a new method for measuring the perceived three-dimensional location of virtual objects is presented, where participants verbally report a virtual object's location relative to both a vertical and horizontal grid. The method is tested with a small (1.95 × 1.95 × 1.95 cm) virtual object at distances of 50 to 80 cm, viewed through a Microsoft HoloLens 1 st generation AR display. Two experiments examine two different virtual object designs, whether turning in a circle between reported object locations disrupts HoloLens tracking, and whether accuracy errors, including a rightward bias and underestimated depth, might be due to systematic errors that are restricted to a particular display. Turning in a circle did not disrupt HoloLens tracking, and testing with a second display did not suggest systematic errors restricted to a particular display. Instead, the experiments are consistent with the hypothesis that, when looking downwards at a horizontal plane, HoloLens 1 st generation displays exhibit a systematic rightward perceptual bias. Precision analysis suggests that the method could measure the perceived location of a virtual object within an accuracy of less than 1 mm.

The original version of this chapter was revised. The acknowledgement was inadvertently forgotten. It has been added.

In room-clearing tasks, SWAT team members suffer from a lack of initial environmental information: knowledge about what is in a room and what relevance or threat level it represents for mission parameters. Normally this gap in situation awareness is rectified only upon room entry, forcing SWAT team members to rely on quick responses and near-instinctual reactions. This can lead to dangerously escalating situations or important missed information which, in turn, can increase the likelihood of injury and even mortality. Thus, we present an x-ray vision system for the dynamic scanning and display of room content, using a robotic platform to mitigate operator risk. This system maps a room using a robot-equipped stereo depth camera and, using an augmented reality (AR) system, presents the resulting geographic information according to the perspective of each officer. This intervention has the potential to notably lower risk and increase officer situation awareness, all while team members are in the relative safety of cover. With these potential stakes, it is important to test the viability of this system natively and in an operational SWAT team context.

In augmented reality (AR) environments, information is often distributed between real and virtual contexts, and often appears at different distances from the user. Therefore, to integrate the information, users must repeatedly switch context and refocus the eyes. Previously, Gabbard, Mehra, and Swan (2018) examined these issues, using a text-based visual search task and a monocular optical see-through AR display. In this work, the authors report a replication of this earlier experiment, using a custom-built AR haploscope. The successful replication, on a very different display, is consistent with the hypothesis that the findings are a general property of AR.