Extending a standard desktop workstation (i.e. a screen, a mouse, a keyboard) with virtual scenes displayed on an Augmented Reality Head-Mounted Display (AR HMD) offers many identified advantages including limited physical space requirements, very large and flexible display spaces, and 3D stereoscopic views. While the technologies become more mainstream, the remaining open question is how to interact with such hybrid workstations that combine 2D views displayed on a physical monitor and 3D views displayed on a HoloLens. For a selection task, we compared mouse-based interaction (standard for 2D desktop workstations) and direct touch interaction in mid-air (standard for 3D AR) while considering different positions of the 3D scene according to a physical monitor. To extend mouse-based selection to 3D views, we experimentally explored different interaction metaphors where the mouse cursor moves either on a horizontal or a vertical plane in a 3D virtual scene. To check for ecological validity of our results, we conducted an additional study focusing on interaction with a 2D/3D Gapminder dataset visualization. The results show 1) that the mouse-based interaction, as compared to direct touch interaction in mid-air, is easy and efficient, 2) that using a vertical plane placed in front of the 3D virtual scene to mimic the double screen metaphor outperforms other interaction techniques and 3) that flexibility is required to allow users to choose the selection techniques and to position the 3D virtual scene relative to the physical monitor. Based on these results, we derive interaction design guidelines for hybrid workstations.

This paper contributes a first comparative study of three techniques for selecting 3D objects anchored to the table in tabletop Augmented Reality (AR). The impetus for this study is that touch interaction makes more sense when the targeted objects are anchored to the table. We experimentally compare touch and a mixed (touch+mid-air) techniques with the common direct mid-air technique. The touch and mixed techniques involve a decomposition of the 3D task into a 2D task by touch on the table followed by a 1D task by touch or mid-air interaction. Results show that: (1) The touch and mixed techniques present completion times similar to the mid-air technique and are more accurate than the mid-air technique; (2) The mixed technique defines a good compromise between accuracy of touch interaction and speed of mid-air interaction.

We experimentally compare the performance and usability of tablet-based and see-through head-mounted display (HMD)-based interaction techniques for selecting 3D virtual objects projected on a table. This study is a first step toward a better understanding of the advantages and limitations of these interaction techniques, with the perspective of improving interaction with augmented maps. To this end, we evaluate the performance of 3 interaction techniques in selecting 3D virtual objects in sparse and dense environments: (1) the direct touch interaction with a HMD; (2) the ray-casting interaction with a HMD; and (3) the touch interaction on a tablet. Our results show that the two techniques using a HMD are faster, less physically tiring and preferred by the participants over the tablet. The HMD-based interaction techniques perform equally well but the direct touch technique seems to be less impacted by small targets and occlusion.