Depth Sensor Based Detection of Obstacles and Notification for Virtual Reality Systems

Walking interfaces offer advantages in navigation of VE systems over other types of locomotion. However, VR helmets have the disadvantage that users cannot see their immediate surroundings. Our publication describes the prototypical implementation of a virtual environment (VE) system, capable of detecting possible obstacles using an RGB-D sensor. In order to warn users of potential collisions with real objects while they are moving throughout the VE tracking area, we designed 4 different visual warning metaphors: Placeholder, Rubber Band, Color Indicator and Arrow. A small pilot study was carried out in which the participants had to solve a simple task and avoid any arbitrarily placed physical obstacles when crossing the virtual scene. Our results show that the Placeholder metaphor (in this case: trees), compared to the other variants, seems to be best suited for the correct estimation of the position of obstacles and in terms of the ability to evade them

The effect of translational and rotational body-based information on navigation

Physical locomotion provides internal (body-based) sensory information about the translational and rotational components of movement. This chapter starts by summarizing the characteristics of model-, small- and large-scale VE applications, and attributes of ecological validity that are important for the application of navigation research. The type of navigation participants performed, the scale and spatial extent of the environment, and the richness of the visual scene are used to provide a framework for a review of research into the effect of body-based information on navigation. The review resolves contradictions between previous studies' findings, identifies types of navigation interface that are suited to different applications, and highlights areas in which further research is needed. Applications that take place in small-scale environments, where maneuvering is the most demanding aspect of navigation, will benefit from full-walking interfaces. However, collision detection may not be needed because users avoid obstacles even when they are below eye-level. Applications that involve large-scale spaces (e.g., buildings or cities) just need to provide the translational component of body-based information, because it is only in unusual scenarios that the rotational component of body-based information produces any significant benefit. This opens up the opportunity of combining linear treadmill and walking-in-place interfaces with projection displays that provide a wide field of view