Inaccurate perception of distances is a known problem within virtual environments. We hypothesize that the inclusion of virtual characters within these environments can improve an observer's ability to judge distances and achieve accurate spatial understanding. We have conducted an empirical study using a desktop display of a small scale environment to evaluate the validity of this concept. We investigated whether the presence and quantity of virtual human characters, as well as the naturalness of their locomotion animations, could improve egocentric and exocentric distance estimations. Preliminary results suggest that static or properly animated characters could improve exocentric estimations, and properly animated characters could reduce egocentric distance compression errors.

We propose the use of virtual environments to simulate augmented reality (AR) systems for the purposes of experimentation and usability evaluation. This method allows complete control in the AR environment, providing many advantages over testing with true AR systems. We also discuss some of the limitations to the simulation approach. We have demonstrated the use of such a simulation in a proof of concept experiment controlling the levels of registration error in the AR scenario. In this experiment, we used the simulation method to investigate the effects of registration error on task performance for a generic task involving precise motor control for AR object manipulation. Isolating jitter and latency errors, we provide empirical evidence of the relationship between accurate registration and task performance.

Immersive virtual environments (VEs) have the potential to offer rich three-dimensional interaction to users. In many instances, however, 3D interaction tasks are difficult due to both the imprecision of tracking devices and the inability of users to achieve and maintain precise hand positions in 3D space. One way to improve upon existing interaction techniques is to dynamically change the sensitivity of the interaction technique based on user input. Previous research has applied this principle to virtual hand-based manipulation techniques; when the user slows down the movement of her physical hand, the virtual hand slows down even more to allow precise manipulation. In this study we extend the prior research by applying the velocity-based scaling principle to HOMER, an existing at-a-distance manipulation technique based on ray-casting. The scaled HOMER technique offers the user the freedom to accomplish both long- and short-distance manipulation tasks with higher levels of precision without compromising speed. We present results from a user study that shows that the addition of scaling to HOMER significantly improves user performance on 3D manipulation tasks.