From: "" Subject: TECH: Virtual IO glasses & Descent Date: Fri, 1 Sep 1995 09:05:14 +0000 Message-ID: Edward J. Holupka asked: > I am looking for a suitable HMD. I have looked at >vitrual-iO 's i-glasses!...........However, I get the impression that the >glasses >are really "toys" and not suitable for developement for a serious >project. >They use the serial port of the PC. Wouldn't connecting to the >ISA/EISA >bus be alot faster? ......... Is it indeed possible to view 3D >perspective images >in the HMD? Virtual IO's glasses are not just a toy (they are a very nice toy as well), but provide a stereoscopic HMD on par with others in their price range and substantially better than 1st/2nd generation HMDs that you would have paid $6000+ for 2-3 years ago. It has a small FoV but if you require maximum possible resolution for your $ then this is an advantage. It will display 3D stereoscopic images if you can produce them. There is no question that the display is capable of providing the capability you require. The built in tracker, however, is a little slow, reports pitch, roll, yaw but not x,y,z and has much lower resolution that the Bird (Ascension) or Fastrak (Polhemus). In this respect the tracker is suitable for games - but may not be suitable for a medical application requiring precise head-gaze info. If you need to you could supplement the I-glasses with a Fastrak or Bird - but then you'd triple the cost (note the cheaper Polhemus "Intrack" is also of relatively low res. compared to the Fastrak). Compared to the market 2 years ago the Iglasses!, Cybermaxx, Forte, 3DMaxx (shutters) etc.. are all bargains and if you have any serious money to spend on your application then you might as well buy one of each ! Jeff Lew asked: >I'm just curious to know if anyone has hacked a HMD to be usable with >Doom or Descent. Descent will drive the the Virtual IO, Cybermaxx and 3Dmax no "hacking" required, just some $. We have noticed however that using Descent with the Iglasses you get a flicking of the stereo-polarity every couple of seconds (the input is a field sequential left, right, left, right video signal, which is then seperated to left, left and right, right) - so you start out with left view to the left eye and right to the right, BUT then it flicks to right view to the left eye and left view to the right eye, and jumps back and forth. We haven't sorted out if this is a problem with Descent, the video encoder or the display but it IS SERIOUS (anyone from Virtual IO listening?). When you see it you may think its tracker-jitter, but be warned that if anything is going to give you a head-ache etc... this would be a prime candidate. If anyone else has Descent connected to an HMD then check this out by closing one eye then the other and look for reciprocal shifts in the image (the image for each eye will jump in opposite directions e.g. - both towards the nose, where as tracker-jitter would displace them in the same direction, e.g. both rightward). John Wann VEL Edinburgh University. http://haggis.psy.ed.ac.uk/