From: dither@vms.macc.wisc.edu (Dennis Adams)
Subject: Re: Question about SEGA's Time Traveller mirror effects
Date: 11 JAN 92 15:31:24    
Organization:  University of Wisconsin Academic Computing Center



In article <1992Jan10.030339.19081@milton.u.washington.edu>, kpc@panix.com 
(Kevin Centanni) writes...

>Has anyone had any experience with Design In Mind's "Micro-Theatre"?
> 
>The technology has been used in an arcade video game by SEGA called
>"Time Traveller".  It somehow uses a parabolic mirror and/or lenses to
>create a 3-D illusion with images coming from a video monitor.  With
>the Micro-Theatre, there are also infrared sensors that work much like
>a touch screen to allow users to 'pick' certain areas in space.
> 
>I'd like to know more about what types of optics are required to create
>this illusion.  Can someone point me in the right direction?  Are there
>other companies that are developing similiar technologies?
> 
>If this sort of thing is feasible for a relatively low cost, I have a
>potential client that would like something developed soon.


I saw the Design In Mind display a while back at a consumer electronics
show.  One very interesting thing about it is that there is only
one image.  It is _not_ a stereoscopic image.  One camera is used to
film the scene.  There is no "depth" to the image, although it certainly
looks like there is, due to the interesting optics.

I am not sure if the "reflection" on the virtual ground
is an artifact of the system.  It was present in the demo, and it is
present in the SEGA game.

The mirrors cause a "virtual image" of the CRT face in the space above
the protective plexiglass.  You can reach out and put your hand where
the image appears to be.

Another interesting aspect of the system is the fact that the image
always seems to be facing you, regardless of where you stand (left or
right).

Anyone know the optics involved?  It would be fun to build a small version.

---Dennis Adams