Subject: Re: hardware support for stereographic viewing

From: [email-masked] (Lance Norskog)
Date: 25 Jan 92 23:22:11 GMT

I compiled this a year ago.  Nothing much has changed.
StereoGraphics corp. has a free book they'll send you,
chock full of 3D projection geometry stuff.
Enjoy!

Lance Norskog
[email-masked]

	3D Viewing Hardware Vendor Survey #3
	Jan. 14, 1990

This survey is limited to companies claiming to ship to anyone
with the bucks (more about this below).  So far, I've found 
three LCD shutter systems, one LCD shutter hack project,
one LCD monitor system, and one LCD parallax system.

This posting is not an endorsement of any vendor or product.

Please send more, I'll maintain this list.

LCD Shutter systems:
	
	Haitex X-Specs 3D for the Amiga line.
	Haitex Resources, Inc.
	Charleston, South Carolina 
	803-881-7518

	Hardware: LCD shutter pair mounted in a welder's visor.
		  Small black box that with an Amiga joystick port
		  on one side and two 1/8" 3-pin jacks on the other.
		  The Amiga side just uses 5V/0 as an input square
		  wave, and feeds a 25V wave to the shutters.
		  You can fan those two plugs out to more shutter
		  sets.

	Software: An arcade game, a molecule displayer, a stereo
		  picture viewer, a few pictures, a utility for
		  taking right&left views generated by ray-tracers
		  and viewing those.

		  List: $110.
	
	Good luck getting ahold of them.

	Vision Research Graphics
	99 Madbury Road
	Durham, NH  03824
	vox: 603-868-2270
	fax: 603-868-1352
	
	Hardware: Reselling Haitex visor, going to their own design.
		  They sell it with a PC Card which drives the visor.
		  Card also listens to signal from VGA/EGA to monitor,
		  notices vertical retrace and does an interrupt.  
		  List: $350 for card/glasses/cable/support.
		  Various other goodies: extra glasses $75,
		  3-axis trackball $150.  (One presumes this means
		  it can be twisted.  Carpal tunnel, here we come!)
	Software: Software development kit.
		  3D routines, switcher hardware driver, binary library.
		  Not clear what's available in source form.

	An engineer answered the phone and we chatted.  He said the Haitex
	visors can run at up to 80-90 HZ before crosstalk makes them
	unuseable.  Several VGA and high-end cards can run at dot clocks
	which support 90-120 HZ performance.

	Crystal Eyes 3D
	StereoGraphics Corporation
	2171-H East Francisco Blvd.
	San Rafael, CA  94901
	vox: 415-459-4500
	fax: 415-459-3020

	Hardware: LCD glasses with an infrared receiver.
		  Emitter sits atop your monitor, you need to be	
		  within 6-8 feet.
		  $995 for glasses & emitter, $845 glasses only.
		  These are the lower grade LCD they sell.
		  The higher grade ones are $2000.  They have better
		  "extinction ratio" and are aimed at workstation users.
		  Various other gizmos for doing stereo video production.
	Software: None from StereoGraphics, but they have a catalog
		  of vendors that support them.  They also have a 
		  listing of monitors and PC cards which support 120HZ
		  operation.  The cheapest monitor lists for $2000.
		  I've seen the Ikegami 20inch (flat tension mask!)
		  in stores for $2000.  The PC cards seem to be $2000+
		  also.

	Their target is pro use instead of home use.
	All their gear runs at 120HZ.  Later their literature
	mentions "extinction ratio" as does the Haitex specification,
	so I think that's the real term; I'm guessing it means
	the amount of light blockage achieved.  They quote 1/100
	as a low-grade ER and 1/300 as a high-grade ER.

	SEGA 3D glasses
	Juri Munkki <[email-masked]>  
	(Mail from the USA had some trouble getting to him.)

	Mr. Munkki has a circuit that takes 12V/0V inputs (the modem 
	ports of any serial port) and controls the SEGA 3D spex.
	If you write him politely, he'll send you the part
	list and a 2-color gif of the circuit.  It's a single-layer
	board, no big deal.  You chip-burners out there, take note!
	The parts should cost $10-$20, and the goggles cost $35.
	They may be out of production, it's a little tough to
	figure out. 

    The general scoop is that cheap shutter systems run at 60 HZ,
    30 per eye.  This gives severe flicker.  The flicker drops when
    you run them at 80-90 HZ, and disappears at 120 HZ.  This corresponds
    to the standard monitor speed spread of 30 to 60HZ.

    Theoretically, a parallel port should be able to drive the
    Haitex.  They need 5V 33mA, which is more than a parallel port has.
    IBM parallel ports don't have a solid 5V out, but the joysticks do.
    You could also bring 5V + ground out from a disk drive connector.
    (I built a Nintendo joystick this way.)
    A serial port could definitely handle the mA, but you need to build
    a voltage divider circuit to feed 5V into it instead of 12V.  I
    flunked electronics; this whole paragraph is suspect.

    Vision Research's current PC card is all analog, like the Munkki
    circuit.  They're doing a new card that uses a ROM to supply
    waveforms to the visors instead of the current analog circuit,
    as this gives better control.  

    Also, a new type of visor material is available which blurs on 
    command instead of going opaque.  The rumor is that this gives 
    the same or better performance as opaque LCD and doesn't make 
    the room dim, because the full amount of light still comes through.  
    We'll see.

    Also, there's a rumor that StereoTek does a glasses set for the
    Atari ST.  Just a rumor.

    My humble opinion (as a severe myopic who is too lazy to mess 
    around with contacts) is that the Haitex visor method is the
    right approach.  They sit on your head, in front of your glasses.
    CrystalEyes and Sega definitely interfere with glasses.  

LCD Monitor system:
	
	EyePhones
	VPL Research
	Redwood City, CA

	Hardware:  Helmet with two LCD monitors: $7500  ??
		   With 3D Polhemus magnetic sensors: $9500 ??
		   The LCD monitors are NTSC.  Some sort of very
		   expensive glove and suit with all sorts of
		   sensors.  Coming Really Soon Now: $200 version
		   Mattel Power Glove with full computer access.
	System:
		   Twin SGI rendering machines are controlled by
		   a Mac. (!!)  $250,000 for research version.
	
	Darling of the media.  Who does their publicity?

	I don't have literature on VPL, and the above description
	is distorted by my memory.

	I tried out the EyePhones (and the famous DataGlove) with
	AutoDesk's software.  It was quite fascinating.  When they
	get rid of the 2-second delay time between movement and
	screen update, I want one.  The EyePhones helmet looks
	fairly rugged, but not enough.  The DataGlove looks
	very fragile.  My glasses were the largest frames in the
	store, and my head size is 7-5/8; the EyePhones fit comfortably.

LCD Interference system:

	DTI 100M
	Dimension Technologies, Inc.
	176 Anderson Avenue
	Rochester, NY  14607
	vox: 716-442-7450
	fax: 716-442-7589

	Hardware: Wacky.  Special screen with no glasses!
		This is a backlit LCD screen from portable computers.
		It's based on vision parallax.  You may need a diagram 
		(which I have and you don't) to visualize the concept.

		The backlight is a grid with very bright thin 
		lines.  The net effect is that light from grid
		line X goes through LCD pixel X to get to the left
		eye but goes through pixel X+1 to get to the right
		eye.  The next grid line over feeds pixels X+2 and X+3.
		This gives you separate control over each eye
		but half as many pixels.  The plate is an inch or two
		behind the LCD screen.  You have to be in the horizontal
		plane of the LCD screen to see the effect, with several
		"sweet spots" in a semicircle around the display.

		The screen is 640x480, giving a 16-level gray scale of
		320x480 pixels.  "Objects seem to come out of the screen
		and extend into it."   Viewing area, 6" x 8".
		328 lines on the backing grid.  

		The full box is 12"x13"x2", tiltable.
		Alleged to be very solid construction.
		List: PC $6300 Mac $7900; comes with special
		Yamaha video controller that speaks to LCD displays.
		(This is very different from a CRT).

	Software: PC and Mac drivers for controlling the display.
		Some sort of 3D cursor library.

	Salesman hadn't heard of the X Window system.  I told him
	PEX was his biggest target market.  Claimed to be doing 
	custom stuff for various biggies (Nasa, Army, etc.).

	If you feel like hacking one of these up from a cannibalized
	laptop, it's very patented.  Sorry, no patent #'s handy.