Oculus Rift DK2

Time for a nice write up on the Oculus Rift Development Kit 2. So, by now nearly everybody has heard about Oculus, a company who is trying to bring Virtual Reality back to life and releasing it's own headset to make that vision reality. It all started with a simple prototype which got into the hands of John Carmack, followed by a hugely successful Kickstarter campaign and as a very sour cherry on top of the cake it got sold of to Facebook. Now, to put it mildly I am personally very interested in VR, so I could write up lots of articles about the past, current and future VR scene, and quite tempted to mix up a lot of those things into this review, but I will try to limit myself purely to the DK2.

The DK2 is the second development kit released by Oculus, meant for (obviously) developers. It however is publicly available for purchase to anybody who's interested, but mind you, as a normal consumer it is definitely advisable to just wait it out for the consumer version which should be released in less than a year. But let's get to the actual DK2.

Cost:	$350 ($400 inclusive which makes for €300)
Resolution:	1920x1080 (960x1080 per eye) (Pentile!)
Display refresh rate:	75 Hz, 72 Hz, 60 Hz
Display persistence:	2 ms, 3 ms, full
Official Horizontal FOV:	> 90° eyes combined
Community measured Horizontal FOV:	84° per eye (4° decrease from DK1)
Diagonal FOV:	Developer kit: > 110°
Head Tracking:	1000 Hz absolute 3DOF orientation (gyr/acc/mag). Positional tracking with near Infrared CMOS Sensor 60 Hz
Connection:	HDMI and USB
Weight:	440 grams (without cable)
Included Accessories	HDMI to DVI Adapter DC Power Adapter International Power Plugs Nearsighted lens cups Lens cleaning cloth

Sources: Link, Link and Link


If you've got the chance to try out the Rift already you can skip this section. For the rest I am going to write up how it feels to try out the rift for the first time:

The above really does sum up the reactions to first demo's quite well. By now I have given tens if not hundreds of demo's and disregarding the individual variation this is what it really does tend to be like. And yes, you would be surprised by how many people actually close their eyes because the experience is too realistic.

Now, before we get back to the DK2 itself, let me give you a very quick run down how the Rift works technically, and how it's different from more traditional Virtual Reality displays. Below you can find a photo of the 'back' side of the Rift with the left lens piece taken out. Behind the lens piece (turned off on the photo) there is a perfectly normal mobile phone display. The lenses simply 'trick' your eyes into making the focus of the display be at infinity (really simplified explanation), thus you're able to see it sharply. The problem? Chromatic aberration. Colours have different wavelengths, and depending on the wavelength the lenses are bending them different amounts, so you get lots of weird colour artifacts (imagine little mini rainbows all over your vision). The trick is to cancel out these artifacts in the software. It's a bit hard to explain well, but imagine that you wore glasses made of very light red see through plastic. One way to make everything look normal would be to make everything in the room a corresponding amount less red. This in contrast to how traditional virtual reality displays worked where a very complex (and expensive) set of lenses was used and a set of dedicated special purpose displays. The strength of Oculus' approach lies in it's high Field of Vision (meaning how much of your vision is filled by the display) and it's cheap component costs, the downside in slightly more expensive rendering cost and small problems with colour representation in some edge cases (honestly, I read an article/paper on them, never actually encountered them myself in the real world).

The first thing you will notice when you open the box that besides the Oculus Rift itself there is a sort of 'webcam' in the box as well. The camera is used for positional tracking which means that if you move your head forward, backward or left and right whilst mounted in the Rift this too will be noticed. The other big change is one you won't notice from the outside, however makes a huge difference when you put the Rift on: the new display and display technology, but more on that later.

Besides those two big improvements a couple of smaller differences can be found too. With the DK1 there was a separate controller box, now the box has been integrated into the Rift itself which makes it slightly heavier, but easier to use. Then the cables management has improved with some of the cables being bundled together back over your head, making the chance you stumble over cables a lot smaller when using the Rift in a standing position. Another big difference is that the Rift now can run from USB power only, which is a big deal if you're into full immersion VR. And lastly they now only provided two sets of changeable lenses (for people who need glasses rather than three sets).

Let's start with the positional tracking. The positional tracking works with a webcam monitoring leds on the Oculus Rift. To get the idea you can see the LED's turned on on the photo below. The interesting part is that with the naked eye you can not see those lights, I was simply taking a picture with my mobile phone camera and suddenly noticed them all over the device.

So, what does all this practically mean? The good part is that the tracking has an absolute point of reference, so drifting - the situation where the computer thinks you're moving more and more and more to the left for example - will not occur. The bad part is however that tracking only works when you're facing forwards and within the view of the camera. There are alternative ways to do tracking, but after a lot of internal testing Oculus decided this was the best way to go... to the surprise of many in the community.

Either way, my expectations of the tracking solution were pretty high. I knew it's limitations, but thought that during normal use one wouldn't really encounter those. Well, what can I say? You will. The boundaries are really quite narrow and the trick is placing the webcam really far away from you. Then angle visible to the camera might work out in a wide space desktop setup, but doesn't work out well with the mobile laptop setup I travel around with. The biggest problem however is that when you leave the monitored area there are no smooth transitions and your head simply makes a little odd jump. Luckily that last problem can be solved by software and I am pretty sure it will be solved too by individual developers, but it's a waste it hasn't been solved in the SDK. Lastly it feels like my head is moving less inside the Rift than in real life, and I have heard other people complain about that as well in the community, but if that's really the case it will be solved soon enough, but it might be just caused by scaling issues of demo scenes.


The other big change is the new 'full hd' display. A pentile display which is also used in the Galaxy Note 3 (assuming the rumors are true). Those who know what pentile displays are might start scratching their heads, for those who don't understand: it means that the display has significantly less pixels than you would expect of a 1080p screen... normally without any additional advantages to make up for that. In the Rift however there is at least one surprising advantage. In the DK1 you would see a black raster over the entire image laid out, a raster made up of the black space in between pixels. With the DK2 you can still see this raster, but due to the pentile layout this means it's a honeycomb shaped layout rather than a simple square raster which for one reason or another is even easier for the brain to ignore than the square one from the DK1. Add to that that the raster is a lot smaller as well and you really get quite the nice effect.

Now, the higher resolution is a huge improvement that can not be understated, however it's still far from perfect and to some extend it feels like we have now officially entered the uncanny valley. Oculus is however facing quite the practical problem in this regard. Although they could increase the resolution of the Rift relatively easily, most computers already have a fairly hard time rendering 1920x1080 - if they're capable of it at all -. There are VR related tricks which can help out in really smart ways, but in the end the truth still is that higher resolutions don't make sense for the consumer market. But enough background info, I was planning on not including things like this at all.

Beyond the resolution the screen itself looks better as well, compared to the DK1 the colors are more vibrant which makes all the scenes look far more real, especially if you go back into the DK1. I wish I now had the fancy equipment Tweakers has to provide you guys with one of those colour distribution graphs, but without that all I can say is that the color balance looks pretty good to me, although maybe it's a bit drawn towards the red side of the spectrum. Still, that's hard to say without proper equipment.


The other display related improvement is the low persistence mode Oculus developed (correction: it already existed for desktop screens, oculus developed the hardware solution for it's own 'mobile' form factor). With the DK1 there was a huge amount of motion blur due to the refresh rate of individual pixels. It's something you normally wouldn't notice that much, however when you have such a display strapped on your head it becomes really apparent. The solution Oculus came up with is not to just use a display with a lower refresh rate, but to turn on pixels only for fractions of seconds. Now, I can go into the tech behind it and explain how it all works, but in the end only one thing matters: Does it work? A clear and resounding yes is the only answer I can give to that. I got the chance to see a demo where they were able to turn of the low persistence mode and the difference was definitely noticeable. Mind you, the new display on it's own is already a whole lot better than the DK1, but the new display combined with the low persistence mode positively solves the problem of motion blur.


One last huge improvement I didn't mention before is not so much an improvement of the DK2 itself, but of the software behind it: The new direct display mode. To understand what it does one first has to take a step back and understand what the Rift is. The Oculus Rift at it's core is just a display, some sensors and a set of lenses. So, when you connected the DK1 it would simply register itself to the Operating System as an external monitor and that was the end of the story. When you wanted to launch a game this meant you had to somehow get it to launch on that monitor - which could be a huge mess - or simply clone your entire monitors which meant running awkward resolutions on your main monitor. With the new Oculus Rift Runtime an alternative is introduced where the runtime intercepts graphic calls and sends them to the Rift. I haven't found the time yet to read up on how exactly it works, but if you haven't worked with the DK1 then believe me that you should be very glad of this development.

Beyond that Oculus has been really busy figuring out a lot of very nice rendering tricks to minimize lag and improve the experience in a lot of different ways. From the way the sensors work, up to the way the rendered image is changed based on information in the z-buffer they are doing everything in their ability to make the entire experience as smooth as possible. It's hard to say how much of a difference those things make, as I can't simply tell the API to turn them off and on on my request (well, some I can, but that's not the case for most), but all in all Oculus is definitely doing a lot of impressive work.


So, the careful reader might have noticed that I mentioned that the rift can now run on usb power, yet the spec list mentions things like a "DC adapter". The story behind this is that although you actually can connect the Rift to the power outlet, however this isn't meant to power the Rift itself, but an USB port on the Rift itself (see below). Is it useful? Not really~ For mobile solutions (e.g. virtual reality simulations where you can walk around in real space) you don't wish to have AC power and for stationary solutions a USB connector on the Rift simply isn't necessary with any of the peripherals that have passed my hands. Only thing I have considered using it for was to mount a webcam on top of the Rift more easily, but that's once again something you wish to do in a mobile setup. Either way, according to everything I have heard so far that port is probably going to disappear in the consumer version (except if some developer has a super popular genius idea how to use it). Aside of the USB port there's another port as well meant for head position tracking/syncing (you could in theory connect the camera to it I think), but it's redundant and illogically placed and as far as I know it's only been used by Oculus itself during development of the prototype.

People with glasses are often left wondering whether they will be able to use the Oculus Rift. The good news is that one way or another the answer is nearly always yes, but let's start at the beginning. There are two basic types of glasses, those that correct for longsightedness (hyperopia, when you need glasses to read) and those that correct for shortsightedness (myopia, when you need glasses to see in the distance). Now, at first glance you might expect that people who need glasses to see in the distance should be fine, as the screen in the Rift is so close to the eyes. Sadly not so. The lenses in the Rift work in such a way that the focus is in the far distance, thus this means that anybody who needs glasses to read has no problem whatsoever using the Rift, however those who see poorly in the distance will need to go out of their way a bit. There are two options, either cramming your glasses inside the DK2 or using the alternative set of lenses that are included. The disadvantage of the first approach is that you have to increase the distance between your eyes and the lenses/screen (which is possible using the dial photographed below) thus decreasing the FoV. Additionally some glasses are too wide to fit in the Rift, but out of the 150 or so demo's I have given I have only seen that once. The disadvantage of using the alternative set of lenses is that it only works in a range between around -0.5 to -2.

That's at least the situation with the DK2, the good news is that with the Consumer Version they will probably present a better solution. I know for a fact that they have explored a variety of options and my guess would be that they will sell specific lens cups for different strengths, but they have been researching more innovative solutions as well, don't get your hopes up for those though. This still leaves people with more specific lens correction needs, like strong astigmatism and other rarer conditions, how and if they will have a direct solution for that is something I have heard nothing about and my personal guess would be that those people will simply need to use either contact lenses or keep using the dial.


One topic that comes up again, and again... and again is people getting and/or fearing to get motion sick/headaches in VR. At this point I am tempted to just quote some of my comments here on Tweakers about this, but let's just give a short rundown of the issue at hand. The brain expects all it's sensory inputs to line up. So, when your eyes tell your brain one thing, but your sense of inertia tells your brain something else, your brain more or less goes: "Screw you". Well, that's quite the simplification, because even if everything lines up one can induce dizziness if that's the goal, but it's definitely the core reason of the majority of all dizziness experienced in VR. Headaches are a tad bit more complex, but let's just skip the specifics and get to the two major practical questions: How much does the DK2 contribute to fixing the issue? And how bad is the problem actually?

Both of the two major hardware improvements help a lot in alleviating the problem. Positional tracking means that when your head moves around (thus sensing inertia) your eyes will see this same movement. And the removed motion blur means the brain is able to keep up to track with any and all movement that's happening, helping a lot as well. It's a bit hard for me to really give you a fair comparison, because using the DK1 over the last year my brain has learned how to handle the discrepancy quite well meaning I don't get motion sick in nearly any demo's. Still, based on reactions in the community I do have the confidence that the DK2 should make a major difference for first time users and the level of motion sickness they will experience. In a couple of weeks time I will start demo'ing the Rift again and I might get back to this review to document their experiences.

Now, as this is such a burning topic I also wish to address it in slightly broader terms. How bad is the problem really? To be honest, I wouldn't worry too much about it. There are two sides to this story. On the one hand, as I mentioned before, your brain is incredibly smart. Without going into specifics your brain might get motion sick the first 10 times, but at some point it just learns how to handle the new input discrepancies and copes with it perfectly. The other side of the story is that developers and especially game developers simply have to take these kind of things into account in their games. A famous example of this is that in Team Fortress 2 players move around at ridiculous speeds (running around at over 180 km/h). Although your brain can get used even to that, it's not surprising that it takes a lot longer for the average person. What that practically means is that games have to stay a bit closer to reality in some ways than current games do. The good part is though that developers are quire aware of that meaning that all in all you shouldn't worry about motion sickness all that much.

(Now, I do feel obligated to add a short post scriptum on this topic: The brain is the most complex system known to mankind... and regardless of what popular science wishes to tell you, the differences from one brain to the next are huge and anything except understood. What this means for VR is that what doesn't cause a headache for 99.99% of the population may suddenly cause it for those last 0.01% (a 'famous' example is how a couple of people get headaches from the lack of perspective shift). So, although for the large majority there is nothing to worry about, there still is a chance you might be one of the unlucky few)


This section really has little to do with the DK2 specifically, but is more about Virtual Reality gaming in general. Let's first start with one huge thing you should realize: it's nigh impossible to port existing games to the Rift. Although you can quite easily add Oculus Rift support to any game (depends on the game engine how easy) there are countless of issues you have to think about next. There is the example I gave before about Team Fortress 2 or for example doors which suddenly make you feel like you're going to hit your head because they're too low, textures on the floor not being by far sharp enough as normally you would never look at them, too complex mouse and keyboard input which nobody is able to find as they can't see their hands or UI which is too big or too small to see. Honestly, the list is quite endless, but the point is mostly that if you want to properly experience VR you need games that were made with VR in mind. Now, the good news is that a lot of new games actually are being developed with Rift in mind (take for example Project Cars which was recently featured here) and in the meantime a lot of absolutely amazing 'demos' have been developed by the community already. These 'demos' as they are commonly called are simply small self contained games ranging from horror to tranquil gameplay-less experiences. And some of the more popular demos are having their own Kickstarters for full versions.

Does that mean you can't play your current collection of games with the Oculus Rift at all? Well you can. In two different ways. For one a lot of (especially indi) studio have tried porting their games. With differing success. You can find a near complete list in the steam store here (for that matter, Steam itself supports the Rift as well), but just don't expect every port to actually be playable (although some are really quite good). The other option is using one of the three third party drivers meant to add support to existing games: VorpX, Vireio and Tridef. Honestly, it's pretty bad. Feel free to try it, but... don't get your hopes up.

Now, in response to some of the comments I will try to give some practical lights on a some of the more popular games I either have first hand experience with myself, or second hand experiences from friends and people in the community.

I will soon be writing separate reviews on a series of peripherals that are incredibly valuable for the VR experience. For those who are curious these are the peripherals that are most interesting and are meant for VR (supporting the Oculus Rift of course):

• PrioVR: Full body tracking, consumer prices cheaper than STEM provided they can deliver on their promises
• STEM system: Full body tracking, consumer prices expensive
• Control VR: Hand tracking, extremely expensive
• OMNI: Passive omni-directional thread mill, got a huge load of attention, but still unsure how good it will be (I got a more or less private demo at a conference once and wasn't impressed)
• Virtualizer: Another omni-directional threadmill, has a couple of additional features and a solution without tracking (as that can be done either way with a full body tracking solution thus making it slightly cheaper than the OMNI)

Lastly the rumormill has been running wild with stories about Oculus presenting it's own input device at Oculus Connect next month (September 19-20th). How that's going to work out is hard to predict, so let's just wait till then.

As it's a development kit I don't want to discuss the price too much, but I did feel like I had to justify the "Good" rating I gave it up above. So, there are two things to be said in this regard which seem relevant. On one hand compared to the DK1 it's $50 more and a tad bit expensive. On the other hand compared to traditional VR displays which cost 2k to 20k it's ridiculously cheap. In the end the Consumer Version should be $300 or less based on the info Oculus has given, so I still think the price is amazing at the current moment and it's only going to get better. (Wouldn't be surprised if it goes down to sub $100 levels in 5 years time)


It's hard to finish such a piece of with a solid conclusion. Right now the DK2 is already an amazing piece of hardware, there is enough room for improvement, however it seems reasonable that most if not all of the 'big' imperfections can be fixed easily in time for the release of the Consumer Version. In the end the Oculus Rift is a device which can and is revolutionizing many markets. Most interest is currently coming from the gaming industries (and rightly so, because it definitely is amazing for gaming), but it's influence will be felt far beyond that in the years to come. And if you will allow me a single line of self promotion; I give demo's and/or presentations to companies if they are interested, feel free to contact me. And to everybody else, comment away with any questions or inquiries you have (in Dutch or English ).

• Make sure to download and install the Rift Runtime. And if you're having troubles just keep restarting.
• Install the firmware update for the Rift. You can find it in the Oculus Configuration Utility up in the tools menu. I am not sure what exactly is fixed by it, as I did it the moment I got my DK2, but still useful not to forget.
• Try out the Sightline: Chair demo.

• 0.7: Added a couple of mini game reviews
• 0.6.2: Note added regarding colours of new display
• 0.6.1: Added note about Oculus' own input device
• 0.6: Added a section about use with glasses
• 0.5.2: And fixed a couple of more spelling mistakes I suddenly noticed..
• 0.5.1: Fixed some spelling mistakes: Lots of thanks to SpX
• 0.5: Added a section about gaming in the rift
• 0.4: I hate the custom how headers are images here on tweakers.net... tried to resist... but gave in as well
• 0.3: Added a piece about the hidden USB and sync port
• 0.2: Bare explanation of how the Rift works added
• 0.1.1: Added a couple of the more interesting peripherals
• 0.1: Definitely needs improvement, but at least it's a solid base Comment to your hearts desires!