Augmented Environments Lab

Abstract

An ongoing research problem in Augmented Reality (AR) is to improve tracking and display technology in order to minimize registration errors. However, perfect registration is not always necessary for users to understand the intent of an augmentation. This paper describes the results of an experiment to evaluate the effects of graphical context in a Lego block placement task when the graphics are located outside of the task area. Four conditions were compared: fully registered AR; non-registered AR; a heads-up display (HUD) with the graphics always visible in the field of view; and a HUD with the graphics not always visible in the field of view. The results of this experiment indicated that registered AR outperforms both non-registered AR and graphics displayed on a HUD. The results also indicated that non-registered AR does not offer any significant performance advantages over a HUD, but is rated as less intrusive and can keep non-registered graphics from cluttering the task space.

Reference

Cindy Robertson, Blair MacIntyre, and Bruce Walker. “An Evaluation of Graphical Context in Registered AR, Non-Registered AR, and Heads-Up Displays”  In Proceedings of International Symposium on Augmented and Mixed Reality (ISMAR08), Sept 15-18, 2008, Cambridge, England.  pages-73-76.

Abstract

Registration errors between the physical world and computer-generated objects are a central problem in Augmented Reality (AR) systems. Some existing AR systems have demonstrated how to dynamically estimate registration errors based on estimates of spatial errors in the system. Using these error estimates, these systems also demonstrated a number of ways of ameliorating the effects of registration error. One central part of this previous work was the creation and use of error regions around objects; unfortunately, the analytic methods used only created accurate regions for simple convex objects. In this paper, we present a simple and stable algorithm for generating the uncertainty regions for complex objects, including non-convex objects and objects with interior holes. We demonstrate how our approach can be used to create a set of more accurate error-based highlights in the presence of registration error, and also be used as a general highlighting mechanism.

Correct boundary for complex objects: a teapot and bunny

Reference

Jiajian Chen, Blair MacIntyre, Uncertainty Boundary for Complex Objects in Augmented Reality, In Proc of IEEE Virtual Reality (VR08), Reno NV, March 2008 [poster]

Abstract

An ongoing research problem in Augmented Reality (AR) is to improve tracking and display technology in order to minimize registration errors. However, perfect registration is not always necessary for users to understand the intent of an augmentation. This paper describes the results of an experiment to evaluate the effects of registration error in a Lego block placement task and the effectiveness of graphical context at ameliorating these effects. Three types of registration error were compared: no error, fixed error and random error. These three errors were evaluated with no context present and some graphical context present. The results of this experiment indicated that adding graphical context to a scene in which some registration error is present can allow a person to effectively operate in such an environment, in this case completing the Lego block placement task with a reduced number of errors made and in a shorter amount of time.

Reference
Robertson, C. and MacIntyre, B. (2007). An Evaluation of Graphical Context as a Means for Ameliorating the Effects of Registration Error. In Proc. International Symposium on Mixed and Augmented Reality, Nara, Japan, November 13-16, pp. 99-110.