Virtual Reality: What do I need?

Don't worry. This is a joke!

OK - now you know what virtual reality isn't, right? It's not the holodeck, it's not the Matrix, it's not the lawnmower man.

If you don't know this, or just want to know what virtual reality is, read this post:
VR: What is it?.

You've heard about it, you've got a good idea what it is, and you'd like to try it. But what do you need?


You don't want to spend hundreds of pounds/dollars on an expensive set up - a fancy headset and new PC. You just want to try it out. If you like it, you might decide to spend that sort of money. But you might not!

So how can you try it out without spending loads of cash on something you might not even like?

The HMD: Head Mounted Display

Creating an immersive virtual experience needs two fundamental components: stereoscopic 3D and positional head tracking.

To achieve the first, you place a small display screen in front of your eyes. The screen is divided into two almost (but not quite) identical images - one for each eye - which create the stereoscopic effect. The user becomes aware of the depth of the image. Objects can move closer or farther away -  like Avatar at the Imax but on a much smaller screen.

Splitscreen display. Your left eye looks at the left image and your right eye looks - well, I think you know. Your brain puts both images together to create one 3D image - just like with Shrek 3D.

The screen is mounted in a headset to become a 'head mounted display' (or HMD for short). The headset usually has straps to hold it onto the front of your head - so your hands are free to hold a bucket in case you throw up. Just kidding!

Positional head tracking is supplied by motion sensors in the headset. As you move your head, that movement is translated into motion on the display screen. For example, if the display is showing you an empty street and you turn around (actually turn around by moving your body), the display changes to show the zombie behind you about to bite your face off. Just before you throw up! Just kidding again!

In the 3D movie globe described above, you turned to look at any part of the screen-globe. In the HMD, the computer has a virtual screen-globe in it's memory and works out which part of the screen-globe you are looking at and displays that image. So look forward and it shows the zombies; turn left and it shows the blonde - and every section of the tunnel your looking at as you turn your head. And it does this many times per second so that the transition is smooth and uninterrupted.

What do you need?

You need a headset with a display screen and motion sensors. A set of stereo headphones is good too, and you may need a hand-held controller to interact with the virtual world. Depending on the headset you have, you may need a desktop computer. And you need virtual reality software or apps.

There are essentially two types of headset.

Oculus Rift

One involves connecting the headset to a PC by a cable and letting the PC do all the heavy work. The best known headset of this kind is the Oculus Rift.

The Rift is currently in development. The DK2 (or Development Kit 2) is the current model. Anyone can buy it but is aimed at software developers, enthusiasts and hobbyists (aka geeks). It can be ordered from the Oculus website for $350 US dollars or about £240. The retail consumer model is expected sometime in 2015 (or possibly 2016). Plus you need a fairly powerful PC to run the software.

The Oculus headset contains a low-persistence OLED display and low-latency positional head tracking - ie a screen and a motion sensor. A desktop PC runs the virtual reality software and the image on the desktop monitor is mirrored on the display in the headset.

A potential purchaser of Oculus Rift wonders where he's going to get $350 from. Meanwhile, the guy behind has pawned his clothes.

But you say "I haven't got £240 to spare - especially not to spend on a prototype that I can't even try out first. There must be a cheaper way to get into this VR malarkey."

And, of course, you are right - there is. Much cheaper.

The second approach to VR is to use a cheap (even almost free) headset. Just a few pounds will get you what you need to find out if VR is for you - or if it makes you nauseous.

Well, how come it's so cheap? What about the stereoscopic 3D display and positional head tracking? What about the computer running the software? They don't come cheap?

That is true, but it's quite probable that you've already got those things with you right now. In your pocket, or on your desk, or even in your hand.

Yes, your phone. If you have a fairly good smartphone with a decent display and gyrosensors, and excellent processing capability, you have almost everything you need to enter the virtual world.

Find a way to position the screen of your phone an inch or so in front of your face and you're almost good to go.

You can build a headset from cardboard. You can download instructions and the plans to make one out of a pizza box.  A bit of sticky tape and some velcro or a rubber band make it better.

But there is one thing (two things actually) that you need that you probably don't have lying around. A pair of lenses. Try holding your phone an inch away from your face. Blurry, isn't it? You need the lenses to focus your vision on the screen.

Once you've got hold of the lenses, building a cardboard HMD (head mounted display, remember?) from scratch is not difficult but it is fiddly and you will probably end up with a scruffy looking headset.

Fortunately, you can buy kits for a few pounds/dollars that have the cardboard pre-cut and contain all the lenses, sticky tape and velcro you'll need. They may also contain two magnets but I'll explain why in another post about the game changing cardboard headset produced by Google - called "Google Cardboard". Catchy name, isn't it.

A Google Cardboard kit with lenses, magnets, rubber band and sticky velcro. Fiddly but cheap.

The assembled headset. Brilliant and revolutionary! But what's missing?

But maybe you don't want a cheap cardboard headset. Perhaps you don't mind spending a few more pounds to get something a bit sturdier and better looking.

Well, you're in luck. There are many, many developers jumping on the bandwagon producing headsets that are attractive in a black plastic sort of way, made of sturdy material with adjustable lenses, headstraps and generally more desirable than a cardboard box. But they all basically do what the cardboard box does.

I will discuss some of these headsets in other posts, but here are photos of the two I own. (I won't show you my Cardboard - it's shamefully tatty.)

The Homido.

The ColorCross.