Support Lines and Grids for Depth Ordering in Indoor Augmented Reality using Optical See-Through Head-Mounted Displays

X-ray vision is a technique where Augmented Reality is used to display occluded real world objects, giving users the impression of being able to see through objects or humans. However, displaying occluded objects means that occlusion is not a reliable depth cue anymore which can lead to incorrect depth ordering. Additional depth cues like support lines and grids showed predominantly positive results with respect to depth perception in AR in previous studies. However, their impact on the ordinal depth estimation in x-ray vision applications has not been evaluated yet. While multiple different designs for lines and grids have been proposed, they have not been compared against each other. We conducted a within-subject user study with 48 participants to explore different support line and grid combinations for x-ray vision in indoor environments. Our results suggest that additional depth cues can result in an increased mental demand and should be selected carefully.