From: Robin Hollands Subject: Re: TECH: compatable HMD's Date: Tue, 25 Jun 1996 12:52:06 +0100 Message-ID: <31CFD2E6.1CB0@shef.ac.uk> Organization: Automatic Control & Systems Engineering, University of Sheffield > Does anyone know if it would be possible to create a homebrew HMD, > possibly with a wide FOV.. (like the 80 degree one described in garage > VR) but make it compatable with comercial HMD's, like the cybermaxx or > others so that it would do stereoscopy in games like descent or > applications in which the cybermaxx or other is supported? Stereo HMDs are tough to build (since its difficult to get the screens close enough together or add additional optics), and even tougher to drive (classically using two computers!) In addition the wonderfully low price of CyberMaxx and VPC HMDs at the moment mean that they work out cheaper than building from scratch (if you buy new TVs, optics, and a PC-Video converter), and they also include head tracking. However, if you happen to have a pocket TV sitting around, and you are prepared to put up with a monoscopic display, you can still save a few hundred bucks by building your own HMD. There is a project in *the book* :-) which shows how to use your monitor for a wide field of view display (basically a large fresnel lens in front of the screen and an enclosure). With the lens round 'the wrong way' the edges of the images are blurred, recreating the effect of peripheral vision and giving the impression of a very wide field of view. A frame-based mechanical tracker can be added which uses the joystick port to provide a sort of periscope control. The fresnel lens optics can be used with most of the low-cost shutter glasses becoming available to provide an extremely cheap wide field of view, high resolution, stereoscopic display. I tried this system with the SimulEyes glasses playing Descent, and the effect was extremely good! Cheers, Robin r.hollands@shef.ac.uk http://www.shef.ac.uk/~vrmbg/staff/rjh/rjh.html