MetaSpace II (MS2) is a social Virtual Reality (VR) system where multiple users can not only see and hear but also interact with each other, grasp and manipulate objects, walk around in space, and get tactile feedback. MS2 allows walking in physical space by tracking each user’s skeleton in realtime and allows users to feel by employing passive haptics i.e., when users touch or manipulate an object in the virtual world, they simultaneously also touch or manipulate a corresponding object in the physical world. To enable these elements in VR, MS2 creates a correspondence in spatial layout and object placement by building the virtual world on top of a 3D scan of the real world. Through the association between the real and virtual world, users are able to walk freely while wearing a head-mounted device, avoid obstacles like walls and furniture, and interact with people and objects. Most current virtual reality (VR) environments are designed for a single user experience where interactions with virtual objects are mediated by hand-held input devices or hand gestures. Additionally, users are only shown a representation of their hands in VR floating in front of the camera as seen from a first person perspective. We believe, representing each user as a fullbody avatar that is controlled by natural movements of the person in the real world (see Figure 1d), can greatly enhance believability and a user’s sense immersion in VR.
In another study, participants had to place a book on a chair at the opposite end of a room by walking across a ledge over a deep pit. The researchers added a real wooden plank for users to walk on, that corresponded with a virtual ledge, and compared the differences in response when the ledge was only virtual. Since participants could feel a height difference between the wooden plank and the floor below, it enhanced the illusion of standing on the edge of a pit. Results showed significant difference in behavioral presence, heart rate, and skin conductivity changes in the wooden plank group of users @cite_53 . Passive haptics have also been used in VR therapy. In one study, a physical spider toy replica was present in the virtual environment so that when the patient's virtual hand reached to touch the virtual spider, she could feel the furry texture of the toy spider @cite_51 .
@cite_53 @cite_51
1489557789 2154968673
One of the most disconcertingly unnatural properties of most virtual environments (VEs) is the ability of the user to pass through objects. I hypothesize that passive haptics, augmenting a high-fidelity visual virtual environment with low-fidelity physical objects, will markedly improve both sense of presence and spatial knowledge training transfer. The low-fidelity physical models can be constructed from cheap, easy-to-assemble materials such as styrofoam, plywood, and particle board. The first study investigated the effects of augmenting a visual-cliff environment with a slight physical ledge on participants' sense of presence. I found when participants experienced passive haptics in the VE, they exhibited significantly more behaviors associated with pit avoidance than when experiencing the non-augmented VE. Changes in heart rate and skin conductivity were significantly higher than when they experienced the VE without passive haptics. The second study investigated passive haptics' effects on performance of a real-world navigation task after training in a virtual environment. Half of the participants trained on maze navigation in a VE augmented with a styrofoam physical model, while half trained in a non-augmented VE but were given visual and audio contact cues. The task was to gain as much information as possible about the layout of the environment. Participants knew before the VE session that their training would be tested by navigating an identical real maze environment while blindfolded. Significant differences in the time to complete the blindfolded navigation task and significant differences in the number of collisions with objects were found between the participants trained in an augmented VE and the participants trained in a non-augmented VE. 11 of 15 participants trained without passive haptics bumped into the next-to-last obstacle encountered in the testing session and turned the wrong direction to navigate around it: only 2 of 15 participants trained with passive haptics made the same navigation error. On the other hand, the assessment of the participants' cognitive maps of the virtual environment did not find significant differences between groups as measured by sketch maps and object dimension estimation. Abstract This is the first case report to demonstrate the efficacy of immersive computer-generated virtual reality (VR) and mixed reality (touching real objects which patients also saw in VR) for the treatment of spider phobia. The subject was a 37-yr-old female with severe and incapacitating fear of spiders. Twelve weekly 1-hr sessions were conducted over a 3-month period. Outcome was assessed on measures of anxiety, avoidance, and changes in behavior toward real spiders. VR graded exposure therapy was successful for reducing fear of spiders, providing converging evidence for a growing literature showing the effectiveness of VR as a new medium for exposure therapy.