Occlusion Effect on Action Space Distance Estimations in Optical See-Through and Video See-Through Augmented Reality

With recent advancements in augmented reality (AR) display technologies, various head-mounted AR displays are now on the consumer market (e.g., Microsoft HoloLens 2, Meta Quest 3). However, there is limited knowledge on how these modern displays impact depth perception. Moreover, understanding the significance of occlusion's effects on action-space distance perception in AR is important, particularly for practical applications such as AR-assisted search-and-rescue operations. However, to our knowledge, no prior research has examined how varying occluder surfaces affect action-space distance estimation across head-mounted AR devices (optical see-through (OST) and video see-through (VST)). In this paper, we present the first research to examine how different occluding surfaces affect action-space distance estimation using OST and VST head-mounted AR devices. With 28 participants across two experiments, we examined verbal estimates and blind walking distance estimation methods. Three occluding surfaces: a checkerboard (high-salient), a black surface (low-salient), and a realistic brick wall texture were considered. Five action-space distances, ranging from 1m to 5m, were evaluated using two commercial AR devices: Microsoft HoloLens 2 (OST) and Meta Quest 3 (VST). Our findings suggest that occluders do not impact AR object action-space distance estimations through blind walking and verbal distance estimation tasks with two modern AR devices. Blind walking distance estimations varied between the HoloLens 2 and Meta Quest 3, with the HoloLens 2 (OST) achieving higher accuracy (distance error: 0.4cm to 3m), than the Meta Quest 3 (VST) (distance error: 24cm to 3m), regardless of occlusion. For AR objects placed on or behind an occluder, distance estimations were overestimated with Meta Quest 3, while the HoloLens 2 either achieved close to accurate or underestimated of depth perception via blind walking.