Abstract
Accurate three-dimensional (3D) depth perception of virtual objects is important for immersive augmented reality (AR). However, it is unclear whether/how 3D depth perception of virtual objects in AR differ from real objects as previous studies have reported mixed results showing both the underestimation and overestimation of an virtual object’s 3D depth. These discrepant results might be due to individual differences in inter-pupillary distances (IPDs), different devices used for research, and the interaction between those two factors. Here, we used a commercial AR device (Epson Moverio BT-35E) and measured 3D depth estimation of virtual objects rendered at reaching (34-50 cm) and room-scale (100-300 cm) distances in a perceptual depth matching task. Specifically, we compared the pixel disparity between the left and the right display calculated from the stereo camera model with the reported pixel disparity during the depth matching task at each distance. Next, we measured pixel offsets due to the mismatch between the inter-display distance (IDD; distance between each display on the device, 6.5 cm) and the individual IPD, and tested whether the calibration based on the individual IPD improve 3D depth estimation. Our results show that our observers (n= 11) overestimated the 3D depth of virtual objects at 34-50 cm and underestimated at 150-300 cm with near-perfect estimation at ~100 cm. Furthermore, our calibration method improved 3D depth estimation at 150-300 cm, progressively reducing underestimation as distance increases (by an average of 45%). Our findings suggest that the 3D depth estimation of virtual objects in AR changes from overestimation to underestimation as the rendered distance increases from reaching to room-scale distances, and that a simple calibration by compensating the mismatch between IDD and the individual IPD may help each individual’s immersive AR experience especially for commercial AR devices without IPD adjustment functionality.