An Exploration of Interaction-Display Offset in Surround Screen Virtual Environments

We present a study exploring the effect of positional offset between the user's interaction frame-of-reference (the physical location of input) and the display frame-of-reference (where graphical feedback appears) in a surround-screen virtual environment (SSVE). Our research hypothesis states that, in such an environment, task performance improves given an offset between the two frames-of-reference. In our experiment, users were asked to match a target color using a 3D color widget under three different display-interaction offset conditions: no offset (i.e., collocation), a three inch offset, and a two foot offset. Our results suggest that collocation of the display and interaction frames-of-reference may degrade accuracy in widget-based tasks and that collocation does not necessarily lead the user to spend more time on the task. In addition, these results contrast with previous studies performed with head-mounted display (HMD) platforms, which have demonstrated significant performance advantages for collocation and the "direct manipulation" of virtual objects. Moreover, a previous study with a different task performed in a projector-based VE has also demonstrated that collocation is not detrimental to user performance. Our conclusion is that the most effective positional offset is dependent upon the specific display hardware and VE task