About Me Research FAAST Curriculum Vitae Publications MxR Lab

Locomotion and Cognition Immersive Virtual Environments


Project Summary:

Navigation is the most common and universal task performed when interacting with a 3D user interface. While moving around in the real world usually occurs without conscious effort, those unfamiliar with computer-generated 3D environments often experience difficulty controlling their viewpoint when immersed in a virtual world. As a result, supporting natural and intuitive navigation is an important goal for the design of virtual environments. Real walking is the most natural travel technique since it mirrors the way people move about in the real world. However, there are notable cost and space tradeoffs to this approach, and the benefits of real walking versus cheaper alternatives has not been sufficiently explored. For my Ph.D. dissertation, I conducted three formal user studies which compared real walking with commonly used virtual steering techniques on measures of memory, attention, task performance, and similarity to real world motions. In general, these studies have identified criteria where real walking provides notable benefits, and conversely they have demonstrated that virtual travel techniques can be effective substitutes under the right conditions.



Real Walking


Virtual Travel


Experiment 1: Complex, Multi-Level 3D Maze

This experiment focused on a complex, multi-level 3D environment designed as a two-story maze with objects placed throughout the corridor. Participants completed the maze using either real walking, gaze-directed virtual travel, or pointing-directed virtual travel, and completed a number of questionnaires testing their memory of the environment. While none of the conditions consistently outperformed each other on the memory tests, our results indicated that for tasks involving the naive exploration of a complex, multi-level 3D environment, the real walking technique supports a more efficient exploration than common virtual travel techniques, allowing faster completion times and fewer collisions with the environment geometry.

E. Suma, S. Babu, and L.F. Hodges, "Comparison of Travel Techniques in a Complex, Multi-Level 3D Environment," IEEE Symposium on 3D User Interfaces 2007, pp. 147-153. (22% acceptance rate, BEST PAPER AWARD)   PDF


Experiment 2: Complex Real World vs. Virtual Maze

In this experiment, we constructed a real world maze with visual and audio objects distributed throughout and modeled an identical virtual environment. Participants explored either the real or virtual maze for a predetermined amount of time using either real walking or a gaze-directed virtual travel technique. Participants that explored the real world maze performed better on tests of memory about the environment than those that explored the virtual environment, but there were no significant differences between real walking and virtual travel. However, analysis of tracker data revealed that participants' movements when using real walking were more similar to real world exploration than virtual travel. Surprisingly, real walking also contributed to greater amounts of reported simulator sickness than the virtual travel technique.

E. Suma, S. Finkelstein, M. Reid, S. Babu, A. Ulinski, and L.F. Hodges, "Evaluation of the Cognitive Effects of Travel Technique in Complex Real and Virtual Environments," IEEE Transactions on Visualization and Computer Graphics, 2010, vol. 16(4), pp. 690-702.   PDF

E. Suma, S. Finkelstein, M. Reid, A. Ulinski, and L.F. Hodges, "Real Walking Increases Simulator Sickness in Navigationally Complex Virtual Environments," poster at IEEE Virtual Reality 2009, pp. 245-246. PDF


Experiment 3: Travel Technique and Gender in a Divided Attention Task

In this experiment, we compared four virtual environment travel techniques using a divided attention task. Participants used either real walking, gaze-directed, pointing-directed, or torso-directed travel to follow a target through an environment while simultaneously responding to auditory stimuli. In addition to travel technique, we investigated gender as a between-subjects variable and task difficulty (simple or complex) and task type (single or divided) as within-subjects variables. Real walking allowed superior performance over the pointing-directed technique on measures of navigation task performance and recognition of stimuli presented during navigation. This indicates that participants using real walking may have had more spare cognitive capacity to process and encode stimuli than those using pointing-directed travel. We also found a gender-difficulty interaction, where males performed worse and responded slower to the attention task when the spatial task was more difficult, but no differences were observed for females between difficulty levels.

E. Suma, S. Finkelstein, S. Clark, P. Goolkasian, and L.F. Hodges, "Effects of Travel Technique and Gender on a Divided Attention Task in a Virtual Environment," IEEE Symposium on 3D User Interfaces 2010, pp. 27-34. (27% acceptance rate)   PDF