When human actors interact with virtual objects the result is often not convincing to a third party viewer, due to incongruities between the actor and object positions. In this study we aim to quantify the magnitude and impact of the errors that occur in a bimanual interaction, that is when an actor attempts to move a virtual object by holding it between both hands. A three stage framework is presented which firstly captures the magnitude of these interaction errors, then quantifies their effect on the relevant third party audience, and thirdly assesses methods to mitigate the impact of the errors. Findings from this work show that the degree of error was dependent on the size of the virtual object and also on the axis of the hand placement with respect to the axis of the interactive motion. In addition, actor hand placement outside and away from the object surface was found to affect the visual plausibility considerably more than when the actor's hands were within the object boundaries. Finally, a method for automatic adaptation of the object size to match the distance between the actor's hands gave a significant improvement in the viewers' assessment of the scene plausibility.

This paper presents a method for measuring the magnitude and impact of errors in mixed reality interactions. We define the errors as measurements of hand placement accuracy and consistency within bimanual movement of an interactive virtual object. First, a study is presented which illustrates the amount of variability between the hands and the mean distance of the hands from the surfaces of a common virtual object. The results allow a discussion of the most significant factors which should be considered in the frame of developing realistic mixed reality interaction systems. The degree of error was found to be independent of interaction speed, whilst the size of virtual object and the position of the hands are significant. Second, a further study illustrates how perceptible these errors are to a third person viewer of the interaction (e.g. an audience member). We found that interaction errors arising from the overestimation of an object surface affected the visual credibility for the viewer considerably more than an underestimation of the object. This work is presented within the application of a real-time Interactive Virtual Television Studio, which offers convincing realtime interaction for live TV production. We believe the results and methodology presented here could also be applied for designing, implementing and assessing interaction quality in many other Mixed Reality applications.

This demonstration is a live example of the experiment presented in [1], namely a method of assessing the visual credibility of a scene where a real person interacts with a virtual object in realtime. Inconsistencies created by actor's incorrect estimation of the virtual object are measured through a series of videos, each containing a defined visual error and rated against interaction credibility on a scale of 1–5 by conference delegates.