Resolving multiple occluded layers in augmented reality

A useful function of augmented reality (AR) systems is their ability to visualize occluded infrastructure directly in a user’s view of the environment. This is especially impor-tant for our application context, which utilizes mobile AR for navigation and other operations in an urban environ-ment. A key problem in the AR field is how to best depict occluded objects in such a way that the viewer can correctly infer the depth relationships between different physical and virtual objects. Showing a single occluded object with no depth context presents an ambiguous picture to the user. But showing all occluded objects in the environments leads to the “Superman’s X-ray vision ” problem, in which the user sees too much information to make sense of the depth rela-tionships of objects. Our efforts differ qualitatively from previous work in AR occlusion, because our application domain involves far-field occluded objects, which are tens of meters distant from the user. Previous work has focused on near-field occluded objects, which are within or just beyond arm’s reach, and which use different perceptual cues. We designed and eval-uated a number of sets of display attributes. We then con-ducted a user study to determine which representations best express occlusion relationships among far-field objects. We identify a drawing style and opacity settings that enable the user to accurately interpret three layers of occluded objects, even in the absence of perspective constraints.