From: ucacajs@cs.ucl.ac.uk (Anthony STEED) Subject: Re: TECH: Walking in VR... Date: Mon, 1 Jul 1996 11:44:04 GMT Message-ID: Organization: University College In article <199606251834.OAA15615@mail-hub.interpath.net> BLADRAC writes: > In response to the talk about walking in VR, what is wrong with roping > off an area and letting the person walk about a room instead of trying > to keep him in one physical position? > > This is the method that UNC adpoted for one of their systems. They > have a square boundary visible in the HMD to let the person know of > the limitations in the real world. > ... > The advantage over using a movable surface or treadmill is that you > are really walking. The disadvantage is that you are introducing a mixed metaphor for navigation - there are two distinct navigation metaphors and this can confuse participants. We had run experiments where we have witnessed people having to decide which navigation metaphor to use. Two cases spring to mind, people starting to move long distances by physically moving and then "remembering" to press a button to navigate when the boundary lines appear or they reach some physical obstruction, and people trying to move a very small distance to reach an object by using the button and overshooting and having to retreat when just taking a pace would have sufficed. I implemented the Virtual Treadmill that someone has already mentioned. This removes any association with navigation from the hand and means it is free for other purposes. It also has a nice feature that has implications for the sense of presence with the environment. When you walk on the spot your proprioceptive state almost matches the optical flow inside the HMD and we believe that this reinforces the sense of presence. This is tentatively supported by the fact that point and flyers don't care so much about where their body is in the virtual environment, and will happily fly through boxes and over chasms. The Virtual Treadmill is fine for situations when you want to give an impression of distance covered, but for fast targetted navigation I personally like SmartScene's grab and scale metaphor. Anthony -- ----------------------------------------------------------- Anthony Steed A.Steed@cs.ucl.ac.uk