Evaluating stereo vision and user tracking in mixed reality tasks!

Advances in head tracking and stereoscopic visualization technologies have fostered the implementation of subjective display systems able to render a 3D scene perspective-corrected according to the position of the user. This enables a whole class of mixed reality applications and interaction paradigms, where the user is able to move freely around the scene and to perform tasks involving the interplay between physical and virtual objects. The accuracy and ergonomics of such tasks strongly depend on the ability of the subjective display system to offer not only a convincing 3D visual experience, but also, and mostly, an accurate rendering of the virtual scene in terms of spatial and metric relations between virtual and physical scene components. In this paper we study the role and impact of head tracking and stereo visualization in mixed reality contexts using a set of measuring tasks involving physical rulers and virtual objects, performed under different rendering conditions. Specifically, we analyze to what extent the two features contribute to give the user the correct alignment between the virtual and the real components of a 3D scene. Finally, we draw some conclusions about their impact within different scenarios.