Earlier this week I was fortunate enough to get my hands not only on YEI Technology's existing 3-space tracking system, but I was also the first to see the true PrioVR virtual reality motion capture prototype. Since the launch of the PrioVR Kickstarter, YEI Technology has demonstrated their vision for the VR tracking system using their existing 3-Space sensor suite. These general inertial sensors can be cobbled together for motion capture, but they aren't made specifically for virtual reality motion capture. The forthcoming PrioVR sensors, which are smaller, cheaper, easier to equip, and higher performing, are built specifically for that purpose. I was fortunate enough to be the first one to see them in action. Showing me the ropes of both the 3-Space sensor system and the first functional PrioVR prototype suit was YEI Technology's Paul Yost, co-founder and head of R&D, and Dan Morrison, R&D developer. They brought with them a full 17 sensor 3-Space system, and an 11 sensor PrioVR prototype. Better Performance Yost told me that while the YEI team worked hard to bring the price of PrioVR down to consumer levels, they didn't throw performance out the window. In fact, they improved it. The 3-Space sensors were design for general motion sensing purposes, not necessarily to be cobbled together into a 17-sensor system. Because each sensor is broadcasting its own wireless signal, the bandwidth becomes saturated quickly, sometimes leading to lost packets and slower transmission than desired -- not to mention the need for a small army of wireless dongles and charging cables. With PrioVR, YEI made the smart choice to work from a single centralized wireless hub which offers a number of cost and performance enhancements. For one, the system needs only one wireless radio instead of 17. This brings costs down while also clearing the airwaves for a single signal (say that 10 times fast), leading to more accurate transmission with much lower chance of lost information. The hub works to reduce costs in the same way regarding the battery -- it uses one larger battery instead of 17 smaller batteries. With these changes, you need only a single wireless receiver and one charging cable -- much more sensible for home use. Yost tells me that the change to a single wireless radio per suit means that you could operate one or two dozen PrioVR suits simultaneously before you start running into issues. Sounds like something the folks from VRCade might find appealing.... Newer technology in PrioVR brings big performance improvements over 3-Space. Bias instability, which Yost told me was "the measure of how good the gyroscope is at maintaining [its] position accurately over time and not drifting" is "an order of magnitude better" in the PrioVR sensors than in 3-Space -- 1.5 degrees per hour vs. 11 degrees per hour. He also told me that the company has spent lots of R&D time on improving the algorithms used by each sensor to determine position and orientation. As for sampling rates and latency, Yost says that 3-Space sensors run around 90Hz while PrioVR sensors are expect to get between 200 - 240Hz at 10ms or less, possibly down to 5ms. He compared it to the Kinect, which has a terribly sluggish 90ms of latency, or the Kinect 2 which is rumored to have 60ms of latency. "We are at one sixth of the next Kinect, which hasn't even been released yet," said Yost. The difference between 3-Space and PrioVR is not just about performance, but ergonomics too. Easier Setup The 3-Space sensors are stand-alone wireless units, each with their own battery and wireless radios, which are on an elastic velcro band. Putting on each of the 17 sensors takes some time -- enough that I could definitely see it becoming a chore to do every time that you wanted to game. PrioVR on the other hand is much closer to a VR motion tracking suit. Four of the chest and back sensors are mounted on a vest which takes just a few seconds to slip on. New glove-like guides, which YEI was showing for the first time, let you quickly slide on the hand and forearm sensors, which takes care of another four. From there two bicep trackers get strapped around with velcro, and last but not least, a strap for the head sensor slips on (the functional prototype they were showing didn't include the leg sensors). The whole ordeal is much faster and easier than putting on individual sensors as with the 3-Space system. Because PrioVR uses one central wireless hub, each sensor is attached by a flexible coiled cord, meaning that the upper body sensors are all held together in their basic shape -- you'll never need to sort through which one goes where, again reducing the time needed to start gaming in virtual reality. And I shouldn't forget size -- the PrioVR sensors are much smaller than their older 3-Space brothers! Continue Reading on Page 2... Gearing up with 3-Space YEI was kind enough to let me try our their 17 sensor 3-Space system, which they've been using in Kickstarter and other demonstrations. They've produced a number of VR demos that work with the 3-Space setup, spanning both Unity and UDK, two popular game engines for Oculus Rift development. Putting on all 17 sensors did take some time. It's easy to see how the suit-style PrioVR layout is going to be much faster to equip. I don't know what all this talk is from folks in the business end of gaming who say things like 'gamers don't want to wear stuff in order to play games.' Pshh... after gearing up with the 3-Space system and the Oculus Rift, I felt like a badass from the future (but I'm sure I looked like a nerd). Cube Demo in Unity I got to step into YEI's unnamed cube demo, built in Unity over the last few days, where randomly arranged red and green cubes float at you. The goal is to dodge the red cubes and touch the green cubes. It was fun, but also harder than it looks! "I think I made it a little too hard," Dan Morrison, R&D developer, told me as he explained that he wanted to make sure there was good reason for the player to move around. Prior to trying the game for myself, I watched Morrison step around the virtual cubes. "It's a much more personal experience when you're in there," Yost told me as I watched. And he was right. One objective is to not let the red cubes touch you. Not 'you' as in your player on the screen, as with most games today, but you as in you. That's my body in there, and I really didn't want it to touch those red cubes. I was avoiding them at all costs -- they were in my personal space. The sense of avatar embodiment greatly enhanced the level of immersion compared to what I'm used to with just the Oculus Rift and Razer Hydra. I mentioned that it might be cool to turn the experience into a Matrix-like game where the cubes are bullets in slow motion and you have to dodge them. Morrison seemed smitten with the idea while Yost started thinking about "non-harmful ways to deliver pain" if the bullets were to strike the player -- a statement that had the three of us laughing when we realized how sinister it sounded... I think we might see more development with this cube game in the future. Positional tracking on the Oculus Rift, afforded by the 3-Space senors, worked very well in the time that I spent in the demo. I was able to lean my whole body around and it felt very convincing with no perceptible lag. Positional tracking is going to add a lot to the Rift. And props to Oculus for a great fit on their development kit. Even while I was ducking, dodging, and weaving through boxes, the unit stayed snug to my face. The same cannot be said of the Sony HMZ-T1 that I used in the UDK demo (below) which required me to hold it securely on my face even if I needed to look down just a few degrees. Oculus has said in the past that an IMU probably wouldn't cut it for positional tracking on the Rift due to drift. However, given an entire skeletal model of sensors to work with, it seems an IMU based system could work very well. With regards to tracking performance, the 3-Space system was very usable, but there's some tuning left to be done to really nail the experience. I think it was a combination of my avatar's size not matching my actual size and some more work to be done on the walking kinematics, but I did feel a bit disconnected at times, like my steps weren't carrying me exactly where I thought they were. Walking in the game uses a kinematic model to actually plant your virtual foot on the virtual ground, then it tracks how far you step with your next foot, and so on. Morrison told me he was still coming to grips with Unity's physics. Based on the experience I had in the UDK demo, it seems like physics tuning, not insufficient tracking, was the culprit. Yost told me that the PrioVR SDK, once complete, will handle most of that grunt work for developers, but they'll also make raw sensor data available to those who might want it. At one point during the demo, my feet got all out of whack. Morrison guessed that some interference in the floor (quite likely, given the studio space that we were in) was the culprit. This caused issue with the aforementioned kinematic walking, and made me drift toward the wall. With the press of a button Morrison told the software to track only the 11 essential sensors, rather than the full 17. Suddenly my legs were back and fully functional. Yost tells me that a more robust calibration sequence will improve experience. At the moment they're using a simple T pose calibration where you stand with your arms out parallel to the ground. Calibrating for a few other poses would help make things even more accurate. In the video you can see that touching my hands together in real life sometimes caused my virtual hands to cross. Without knowing how long each player's limbs are, there's no way to nail that. However, you can pose with your hands touching and calibrate, essentially telling the computer 'this is what it looks like when my hands are touching together', and then it will know for every time after that. Even with a single pose for calibration, I had no issue turning, ducking, and crawling around on the ground of inside the virtual space. As far as I could tell, the direction of my body never drifted either -- I remained facing in the same direction in both the virtual and real worlds. UDK Demo The UDK demo I tried was also using the 3-Space sensor system, along with the Sony HMZ-T1 (they haven't yet rigged it up with the Rift); it's the same one you see in the PrioVR Kickstarter video where they're kicking over boxes. It felt even better than the Unity Cube demo -- the avatar embodiment felt really cool because my avatar was wearing armor. My limbs felt fully like my own. Mark my words: once we have these full body VR tracking systems widespread, avatar customization is going to be a big deal. There were boxes on my left and right to be knocked over, which was somehow lots of fun (probably because actually using your body to do something in the game is a significantly more engaging experience than 'press X to knock over boxes' or 'pull trigger to swing sword' that we're all used to. There wasn't much else to the demo, but it got me very excited to see full implementation of PrioVR in a proper game. Continue Reading on Page 3... PrioVR Prototype After I got to check out the forerunner to PrioVR, Yost donned the PrioVR prototype to demonstrate its capabilities. They haven't yet integrated it into the Unity or UDK demos, but they did have it running with their internal Mocap Studio software. Rigged up to the tracking points was the upper body of a human skeleton (remember, the PrioVR prototype I saw was only upper body). As expected, I saw Yost's actions mirrored on the screen by the skeleton. The demo uses a similar kinematic walking model as the Unity and UDK integration, but because it was only an upper body, I watched as Yost caused the skeleton to walk around using only it's hands -- it was pretty creepy. Beyond seeing a creepy skeleton run around on its hands, the demo showed me something impressive. I had Yost sit down in a swivel chair to see how the system would handle repetitive spins in multiple directions. This is exactly the type of scenario where I would expect to find accumulation errors from a purely IMU based system -- where small errors add together to reveal large drift. To my surprise, PrioVR seemed spot on as Yost swiveled in the chair and always ended up facing back where he started. Though I was initially skeptical of an IMU-based system, I came away quite impressed with PrioVR -- it seems like an entirely viable option for VR motion tracking. After spending the day with Yost and Morrison and hearing them talk tech, I came away with the realization that these are some very smart folks. Yost told me that he started his career in academia but was frustrated by producing exciting research the ended its life as a publication rather than a product. He co-founded YEI Technology so that he could see his work put to use -- and it is -- the company is responsible for AI technology that's being used in the healthcare field, among other projects like 3-Space. They're also running their own manufacturing operation for their products. I get the sense the YEI Technology is pursuing PrioVR not because they have to, but because they want to. And for that reason, I have little doubt that they will pull it off. Full Disclosure: YEI Technology is running a PrioVR ad on Road to VR.