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Tag Archive: Virtual Research

Bookshelf: Sex, Drugs and Tessellation

SexDrugsTessellationCover

Hot off the press is Ben Delaney’s authoritative new book, Sex, Drugs, and Tessellation which collects 6 years of wisdom from Ben’s CyberEdge Journal, the go-to virtual reality publication from 1991 through 1996. Ben has always been both a proponent of, and realist about VR, offering insightful market insights and lucid explanations of ofttimes opaque technology. Both students of VR and grizzled veterans will find Ben’s writing to be illuminating. You may remember his appearance on the PBS series Newton’s Apple where he explains the workings of the Virtual Research Flight Helmet.

An abbreviated “book jacket” summary:

Did you ever wonder who built the first head-mounted display? Who first detailed a coherent theory of Cyberspace? Who wrote about cybersex and the challenges it creates? Who worried about addiction to VR? Did anyone ever cure cyber-sickness?

From 1991 to 1996, CyberEdge Journal covered these stories and hundreds more … … Appreciated for its “No VR Hype” attitude, CyberEdge Journal was the publication of record for the VR industry in the 90’s….

Now that VR is enjoying a renaissance, it’s time to understand where it came from, and avoid making the same mistakes that were made in the first golden age of VR, the 1990’s. It’s also a good time to remember the excitement and sense of adventure that characterized those time.

Sex, Drugs, and Tessellation describes not just some of the hot topics of VR, but also the origins, issues, and solutions that were chronicled in the pages of CyberEdge Journal. Complemented by over 100 photos and drawings, there is a surprisingly contemporary feel to these old articles. In addition, more than a dozen VR pioneers have contributed new reminiscences of their work in VR.

Vintage VR-4 Head Mounted Display Teardown

Here’s a much more detailed tear down of the Virtual Research VR-4 Head Mounted Display, done by one of the engineers at VR sometime in 1994. He shows us how to remove the back light inverter and the main PCB.

‘Scuse the vintage VHS EP mode recording. I was trying to save on video tape costs; a 6 hour tape cost $1.50!

Awesome VR Optics for 1″ Class Displays At Less Than Ten Dollars!

Professional wide field of view Virtual Reality optics for less than the price of a couple of double lattes! A while back I demonstrated a design for Leep On The Cheap, a proof of concept for wide field of view optics on 3″ to 4″ display panels. Trouble was… there was quite a bit of distortion and chromatic aberration. However, it sparked quite a bit of thought and development in the VR DIY community. They’re the ones doing all the heavy lifting.

32mm Erfle Eyepiece

32mm Erfle Eyepiece

So… it’s time to come back with another optical design for wide field of view VR, but this time the optical qualities are first rate and remarkably inexpensive. Of course there are a new set of trade-offs: field of view is limited to about 65 deg. (not bad, but not totally immersive), and I rely on somewhat smaller display panels, about 1″ to 1.5″ diagonal. This is roughly the same as the: Nvision Datavisor LCD, Visette Pro, and Virtual Research VR4/V6/V8.

This design, and many commercial versions, rely a the unique characteristic of telescope eyepieces: that they can be directly used as HMD optics without modification. Even better, they’re made in fairly large quantity, with a large selection of optical characteristics and quality, and somebody else has already solved the issues of distortion, chromatic aberration, internal reflections, coatings, and aspheric design. Did I mention that they’re inexpensive. The sweet spot are either Erfle or Plossl designs; Erfle offers wider field of view. Even wider fields can be achieved with variations on the Nagler design, but the weight becomes prohibitively high.

It’s easier to give the tour by video… viddy this my droogies:

Lens sources:

30mm fl Erfle from Surplus Shed – $9.50

32mm fl Erfle from Surplus Shed – $12.50

I’ll leave you hanging re: the LCD panel. The one in the video shown above was torn from a Virtual Research V6; low res, old school.

More info on eyepieces:

Wikipedia

Common Telescope Eyepiece Designs

 

It’s All In Between The Eyes

If you look yourself in the eyes, you’ll start to realize that your eyes and your head are different than anyone else’s. The spacing between your eyes, known as the interpupilary distance is about 65mm, but this varies from 50mm to about 75mm, depending on who’s eyes you’re looking through. Also the position of your eyes, relative to the shape of your head is unique; some people have eyes that are more inset, or perhaps bulging outward.

The designers of VR helmets have to deal with all this variation in the human phenome. Everyone has a sweet spot where the two lenses of a VR helmet are perfectly aligned with their eyes. Similarly, each of us want the lenses to be positioned as close as possible to our eyes (to achieve wide field of view), without discomfort. If you wear eyeglasses, you need to have room to fit your glasses between your eyes and the lenses.

So… let’s look at how one helmet design deals with these issues:

Siggraph ’95 – Upon Further Observation

Who can remember doing all their 3D animation in MS-DOS? Back in the day, there was Gary Yost’s 3D-Studio (not Max!) licensed to and supported by AutoDesk. Now, who remembers creating stereoscopic animation with 3D Studio? VREX had a great little plugin that setup linked stereo cameras and let you render twice, once for left and again for right. Much fun on a 386!

In sorting through a carton of old BetaCam-SP tapes from the mid ’90s, I came across a non-so-cute animation I produced with the ever imaginative (and twisted) Steve Speer for Siggraph ’95. “UFO” (Upon Further Observation) defies categorization… so get out your red/cyan glasses and watch out for the a**l probe!

At Siggraph, UFO was shown in a bank of a dozen Virtual Research VR-4 helmets with shaker seats.

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ufoposter
ufotheater1
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And for those of you nostalgic for the days of animating in MS-DOS….

Flight Helmet – Redux

IMHO, the Virtual Research Flight Helmet was, and still is, the ultimate head mounted display, except of course, it needed modern high resolution LCD panels. Otherwise, it had incredible field of view, great ergonomics, and unbeatable LEEP optics. I came across a more complete brochure including the retail price list (starts at $6,000.)

Flight Helmet side view

photo: Raz Fairlight

Flight Helmet Optics

photo: Raz Fairlight

One unusual aspect of the Flight Helmet was that the left and right images don’t completely overlap, producing a wider image than the normal 4:3 aspect of NTSC video. If you wanted 100% overlap, you needed to purchase prisms (3M Press-On Fresnels) to shift the images horizontally into alignment. To run the helmet monoscopically, the prisms are a must!

Teardown – Virtual Research V6

1995 brought us the V6 head mounted display from Virtual Research, the successor to the excellent design of the VR-4. The V6 doubled the overall resolution while retaining the great optics, field of view, comfort, and ease of use originally found in the VR-4. In addition to improved image quality, the V6 refined many of the mechanical elements pioneered in the VR-4, greatly simplifying these mechanical elements. The VR-4 had quite a number of circuit boards inside the helmet, but the control box could have been built completely from Radio Shack components. The V6 moved almost all the electronics into the control box, leaving the helmet with a minimum of electronics.

The V6 manufacturing process did not require any expensive tooling, such as injection molds. The plastic parts are either thermoformed or milled in a machine shop. The metal parts are either stock or machine shop fabricated. Great for short and medium run products! The VR-4 used extremely thin thermoform plastic for light blocks and circuit board mounts. This plastic tended to crack and break off over time. The V6 totally eliminates this thin plastic and uses sheet metal (anodized aluminum) and milled plastic instead.

The V6 was followed shortly by the V8, again doubling the resolution. The V6 and V8 share the same control box, power supply, and mechanical components. The V8 adds a small fan inside the helmet shell to cool the electronics and LCDs. The displays and driving electronics are from Epson.

Specs in the brochure…

LEEP On The Cheap

Build your own LEEP style wide field of view head mounted display optics. Check out the instruction video and parts list below.

In the late 80’s and early 90’s wide field of view head mounted displays were all the rage; immersion was everything! The dominant HMD vendors, VPL Research and Virtual Research shared the same optical implementation: lenses from LEEP Systems. These wide angle optics (designed by Eric Howlett of LEEP), coupled with 2″ or 3″ LCD screens really did deliver a totally immersive visual experience…except that the resolution of the LCDs were so low that under this extreme magnification each pixel looked like a football; you were swimming is a sea of colored footballs!

LCD Screens and LEEP Optics

By the mid 90’s (and up to the present) a primary design criteria for head mounted displays was small size and light weight. Indeed there are entire head mounts that weigh only a few ounces and look almost like sunglasses. Sadly, immersion and wide field of view were abandoned. The new generation of head mounts had 20 – 30 deg. field of view. You felt like you were looking through a distant window.

For reasons which I will cover in a forthcoming post, wide field of view and small/light head mounted displays are mutually exclusive. Anatomy and physics bars the way.

Almost 20 years ago I demoed an early Virtual Research Flight Helmet complete with LEEP optics. Being very impressed but unwilling to drop six grand into my first head mount, I set about building my own. The Radio Shack LCD TVs that I found were very similar to the Sony TVs in the Flight Helmet and I set about installing everything in a Friday The 13th style hockey mask. The optics were my biggest challenge, but the answer was buried in Eric Howlett’s LEEP patent, not as a claim, but as a demonstration of how to achieve wide FOV with conventional optics.

So… here’s a brief video recreating that optical design from 1991. I’ve cheated a bit by using my Android phone as the LCD screen, but otherwise the optical path is essentially the same. Aside from the phone, there’s about $25 in parts for a single eyepiece and it can display almost 90 deg. (diag.) field of view. The lens mounting is extra cheesy, but it demonstrates the optics quite well, and only takes 5 min. to assemble. So without further ado…

In the video I mention that someone needs to write an Android application to make it into a fully tracked head mount. After editing the video I remembered and tried out a couple of popular Android apps: Google Sky and Layar, both of which use the position sensors for a full 3D view. They work great with this lens system!

Parts List:

  • Anchor Optics Plano Convex Lens AX73263 43mm dia. x 77.0mm FL – $10.50 (Eyepiece)
  • Anchor Optics Double Convex Lens AX73424 62.8mm dia. x 72.4mm FL – $13.50 (Objective)
  • 2″ PVC Coupler
  • Small Sheet of Polystyrene plastic – 0.030 Black Sheet

If you were building this for real, you’d spray paint all the plastic parts to a black matte finish. LEEP also beveled the edges of the eyepiece lenses to make a better fit with the nose. To reduce weight, switch from glass lenses to CR39 plastic lenses.

If you assemble 2 of these with LCDs, you may find that the eyepieces are too far apart to match your eye spacing. Simply turn the two optical assemblies so that the LCDs point slightly outward and the eyepieces come closer together. Then apply 3M Press-On Fresnel Prisms.