An approach to comparative studies in CAVE using a virtual black wall

Comparative studies involving CAVE systems inevitably have some confounding factors. Except for the six-sided CAVE systems, the missing back wall(s) of a CAVE system can be a confounding factor when virtual and physical navigation interaction techniques are compared, regarding the viewpoint rotation. We introduce a virtual black wall as a way to avoid a possible confounding factor in comparative studies. Based on our pilot study, we found that the virtual black wall can provide the comparable experimental condition for the two types of navigation interaction techniques and that the wall can play a dual role as an obstacle and a landmark during navigation. These findings provide a stepping stone for further investigation of the virtual black wall.