There’s a silent war brewing over the short-term future of virtual reality. It centers around how VR users are going to free themselves from the tethers that are currently part and parcel of the AAA premium VR experience. Yes, there are mobile and self-contained VR headsets, but none of them can compare to the fidelity and experience of a tethered HMD hook-up on a cutting-edge computer with the latest graphics technology.
The hardware needed to meet the minimum standards have indeed already shrunk down a lot; so much so that VR-ready ultrabooks such as the Razer Blade are possible. However, it’s still simply impossible to stick that level of hardware into a self-contained unit. So how do you get rid of that long tether and still have access to those powerful computational resources you need for cutting-edge VR? This isn’t just for VR gamers who feel inconvenienced – there are plenty of training and industrial applications for truly high-end VR that isn’t literally tied to an anchor.
Two Ideas are Better than One
Right now there are two approaches to solving the tethering problem. The obvious one is to create an HMD that can transmit its data wirelessly. The problem with this is that devices like the Oculus send massive amounts of data in both directions. The main killer here is the double HD 90 Hz video signal. The motion-tracking data going the other way is pretty beefy too.
Bandwidth isn’t even the whole story. With aggressive compression you can get it through a thinner pipe, but going wireless and still keeping the entire latency loop under 20ms has so far proven essentially impossible. In fact, measures such as video compression actually add to the total latency, since it takes time to squeeze those frames down before sending them over to the airwaves.
Despite these technical challenges, VR pioneer Oculus seems to be on the verge of releasing in 2018 the first practical wireless HMD. It’s a product that’s gone under the name “Santa Cruz” so far; it seems the time for it to come to market is getting close.
The other potential solution towards untethered AAA VR isn’t quite as compact and elegant compared to the concept of wireless HMDs. It is, however, something you could buy today if you had deep enough pockets.
Enter the Backpack VR Computer
HP has taken the genius step of taking all those compact, laptop-friendly components and putting them into a battery-powered chassis that can be strapped to your back. This means that the tether is now anchoring you to something that will go wherever you go. You can turn around to your heart’s content without getting tangled up.
The specifications of the two backpack computers offered by HP are right up there. This is a workstation-class machine, so you get a Pascal-based Quadro P5200 GPU with 16GB of RAM and an i7 vPro CPU. When you are done with the VR portion of your task, you can unclip the machine from the backpack harness and then plonk it down into its docking station. Of course, this convenience has a price tag – it starts around three grand, and that’s before you buy your HMD.
The fact that the backpack form is currently expensive is beside the point, however. The big question to me is whether this is an overall better idea than a wireless VR headset.
Why is a Wireless HMD So Important?
That’s the question, isn’t it? There are so many complex technical questions that have to be solved in order to connect the HMD wirelessly to a computer that I seriously have to question if it’s worth it. Although the backpack computer might look a little cumbersome now, by this time next year they’ll be squeezed into an even smaller box. Even now the whole HP Z computer backpack setup weighs about 4 kilograms. I doubt the typical adult would even notice that weight on their back, and that’s just a first-generation design.
Wireless tethering would be a technological marvel, but is it an over-engineered one? There are so many things that can go wrong with wireless transmission that the very idea of using it for anything other than the least mission-critical task is rather laughable. The only real place it makes sense is if someone already has an existing VR setup and now needs to get rid of the tether.
The thing is, how long before the backpack form factor just becomes another style of case you can buy. Slap your own components into it and there you go. Now the backpack solution becomes an upgrade or a minor conversion. Has Oculus thought this through?
Playing with Wire
Keeping everything connected with a direct wire link ensures reliable performance. This is the age of power-efficient, desktop-grade components. They don’t make a lot of heat and noise anymore. Mechanical drives are optional. With computers now so small and light, there may be no reason at all to leave them on the floor.
The real problem, if you ask me, is the reliance on an external tracking camera. That’s what really ties the VR user down. There’s no indication that Santa Cruz will be any different at this point. That’s a problem, because Microsoft and its hardware partners have essentially made external camera tracking obsolete with Windows Mixed Reality headsets. These new HMDs have outward-facing cameras that track the room, not you – which means if you combine them with a battery-powered VR backpack you can go wherever you want.
Yes, I have to admit that this is probably an application more suited to mixed reality applications. Still, even if complete free-roaming VR is not really practical, the freedom of movement and relatively large space afforded to us by having a backpack-based VR system are features not to be sniffed at.
Betting on a Winner
Here’s the bottom line, from my point of view. They’re spending all this time and money developing wireless display technology. The main reason they are doing this is because there’s no way to build the processing power of a full computer into something as small as an HMD. That’s fair enough, but VR-ready hardware has already been reduced in size to the point where it goes in an ultrabook chassis. We can’t really be that far from AAA VR hardware fitting in an HMD or a small tethered box worn on the belt or elsewhere on the body.
Right now VR backpack computers might seem a little silly, but give it a few years and more size reduction and it could be a completely different story.