Movie Night

In my virtual reality company, we demo our product to many people. It seems that everyone has their favorite movie including a head-mounted display. Some of the common ones we hear are:

• Disclosure
• The Lawnmower Man
• Star Trek (as in 'can you create a Holodeck?')
• Demolition Man (though no one remembers the name of the movie, only Stallone's HMD scene)
• Vanilla Sky

and an honorable mention to Forbidden Science, a late-night series that used one of our products as a prop.

The Year of the Lightweight HMD

I think it's time that the weight of professional HMDs (those with high resolution and wide field of view) gets measured in ounces (or grams) and not in pounds (or kilograms), and I think this will happen in  2009.

Weight is so important in HMDs that it is sometimes overlooked. Lower weight means greater comfort. It means the ability to wear the HMD for longer amounts of time. It means that you can almost forget you are wearing it. Balance (as opposed to front-heavy) is also important as it impacts neck strain. Sometimes, HMD vendors add a counter weight in the back to balance their front-heavy design, but that's clearly the wrong solution.

Why do professional HMDs have to be heavy? The traditional thinking is that this is like asking why a manned fighter jet has to be heavier than an unmanned plane (e.g. drone or UAV). The pilot and flight suit add about 100 Kg to the jet, but that's just the beginning. Now you need oxygen, and a seat that you can eject, and instrumentation you can read. Before you know it, you need larger engines to carry this weight and longer wings and more fuel, so the net difference is much larger than the weight of the pilot.

Traditionally, that has been the thought of professional HMD vendors. The idea was that if you want wider field of view, you need a large lens, and to minimize distortion it needs to be complex and heavy. If you needed high resolution, you had to use more expensive display elements that needed external lighting (and a way to diffuse the light so that it is even). Before you know it, professional started equating with heavy. Heavier designs meant larger (and yes, heavier) head mounts.

Not good. 

And not true. At least not for long. By using new types of displays, optics and components, professional is no longer heavy.  New products, such as the xSight weight about 10-12 ounces. Not quite as light as some of the consumer HMDs in the 'Skymall magazine', but getting there.

So will this be the year of the 'good enough' professional HMD that combines wide field of view, high definition and light weight? I hope so, and I think it will.

Harvard Business Review covers Virtual Worlds

HBR published a short piece last month titled "Getting Real About Virtual Worlds" in which Paul Hemp talks about the business benefits of using 3D environments. Coverage by the Harvard Business Review, given its stature and high-level distribution, is a good sign for an industry.

To me, the article underscores once more the notion that compelling, useful content is already out there. Unlike many non-impressive virtual reality offerings in the 90's, CPU and GPU power is good enough to create a very compelling experience...if you have a good-enough display system.

Using these compelling 3D worlds on a desktop monitor - usually in 2D - is like watching a new High-Def DVD release on a small black&white television. Try it on a high-resolution HMD with wide FOV and good peripheral vision, and you'll never want to go back.

The HMD and the Washing Machine

Should see-through head-mounted displays be also used for completely immersive (non see-through) applications? Technically, it's certainly possible. Just put a dark cover on the front glass, and you have something similar to being completely immersive. However, having the extra weight, the not-quite-as-bright image and a bulkier product is certainly a downside for dual-use HMDs.

This reminds me of the washing machine / dryer combination. What a great idea on paper - no need to move laundry from one to the other. In practice, there are so many drawbacks to this combined approach that most everyone still has separate washers and dryers.

Not to showcase my age too much, but as a teenager I owned an Apple II computer. Not an Apple IIc. Not an Apple IIe. A real Apple II (serial number had 4 digits) and at that time, it would connect to our standard TV through a small conversion box. But, even though it made sense at the time, computers migrated very quickly to separating the TV from the computer monitor. Same concept, different time.

So... I still think see-through HMDs and fully-immersive HMDs should be kept separate for now.

The Mind-Reading Virtual Binoculars

Northrop Grumman Corporation (NYSE:NOC) announced that it was awarded a contract to develop electronic binoculars that use brain activity to detect threats. The press release is here. My company is proud to partner with Northrop on this project.

The project seeks to present a panoramic day/night optical system to a user and monitor brain waves - yes, brain waves - to detect targets of interest. A panoramic view and high-resolution image was deemed very important for this project, which is why Sensics panoramic displays were chosen.

However, the drive to present users with diverse visual stimuli and measure brain activity is certainly not unique to the defense markets. We are working with several academic institutions to achieve much of the same goals within a research context.

Presenting users with narrow field of view displays could be considered not to put the human brain to full use as a super-fast object/pattern recognition computer. This is especially true given that difference parts of the visual field are used for different purposes: central vision is used for reading and perception of fine detail. Peripheral vision is used in humans and also in animals for threat detection, sensing movement and presence of peripheral objects. Try walking around with toilet paper rolls on your eyes (see this demo on the Washington Post) and you'll understand how critical peripheral vision is.

See-through HMDs have lots of ground to cover

See-through HMDs (sometimes referred to as 'personal displays') are sometimes portrayed as combining eyeglasses with a video ipod. In a perfect world, they look like cool fashion accessories, are so light that you can wear them anytime, yet overlay what you see through them with computer-generated images. Perhaps it's a movie that you can watch on a plane. Perhaps it's driving directions or text messages from your friends.

However, to get there, many problems remain to be solved:
- Brightness: can these devices be used in a sunny day?
- Weight: can you really walk around with them all day?
- Power consumption: how long does the battery last and where is the battery placed? If the battery is part of the HMD, it adds weight. If it's on a belt-clip, it adds inconvenience and perhaps a cable.
- User interface: how can you control what information is displayed, or when it is shown.
- Dual use: if the goal is to watch a movie, it's often better to block out external imagery. But how? Do you add a cover to the front? Do you make the glass part so dark that it's effectively like sunglasses?
- Placement of information: if the information is placed in the central vision, it might intefere with reading tasks. If it's placed in the peripheral vision, it is difficult to read. If it's both, you need a very wide display element.
- Stereo vision? At some level, a monocular display (one eye) might be sufficient for textual information. However, if you're looking to augment a scene, the feeling of stereo may be very important. Stereo, however, nearly doubles the weight, cost, power consumption and cabling requirements of the display electronics.
- Sound - can you or should you integrate the display with an earpiece
- Cost, for obvious reasons

I'm curious to see what Apple (who recently published some patents on this) and Sony (recently showing a cool display at SID 2008) have up their sleeves for this product category.

The Alienware curved monitor and a curved HMD

Earlier this year, Alienware (now part of Dell), demonstrated a high-resolution, panoramic monitor. The 'Curved monitor' blends together four DLP projectors to create a wide display that is over 3 ft wide and has 2880x900 pixel resolution. You can read the Gizmodo review of this monitor, and see some videos at here

The process of tiling together multiple displays to achieve a curved, panoramic, high-resolution product is exactly what my company does to generate a curved, panoramic, high-resolution head-mounted display. The multiple displays are positioned so that they approximate a sphere around the eye, for a 'surround video' experience. Resolution is similar or higher than the curved monitor.

The decision whether to use a curved panoramic HMD or a curved panoramic monitor
is a bit like comparing a car to a plane: there are uses where one is better than the other, with some area of overlap. If you need many people to see the image at once, a monitor is better. If you are not inclined to wear anything on the head, the monitor is better. However, if you want stereo images, if you need portability, or if you want 360 degree immersion (image changes when you move your head), the HMD is your choice.

Some of the things I'm curious regarding the curved monitor:
- Does it require special video output modes, or can it accept stadnard display resolutions?
- How many video inputs does it require?
- How good is the tiling/stitching between the displays? In the Gizmodo video you can clearly see the seams between the projectors. Is there a way to achieve a seamless image?
- From a manufacturing standpoint, how does Alienware perfectly align the DLP projectors to achieve pixel-by-pixel matching? Does this alignment change over time?
- How good is the projector-to-projector color matching?

It's great to see tiled displays hit high-end consumer applications. I'm looking forward to trying a curved monitor one day soon and comparing it - with the same application - to a curved HMD