HTC Vive Senior Engineer James Xiong has provided a Vive IK Demo on GitHub, which includes a reference source code and Unity demo. Using the HTC Vive headset and controllers combined with three Vive Trackers, the program uses hardware tracking and inverse kinematics to pose a virtual model that closely matches the human player.

By tracking a headset and two motion controllers held in the hands, developers are able to achieve a reasonably accurate virtual representation of the upper body. In some VR experiences, the user is able to look down and see a full body avatar, but this is often avoided, as there is too much guesswork involved in animating the lower body.

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Making use of the new Vive Tracker pucks, which recently went on general sale, full body tracking can be achieved. The Vive IK Demo requires strapping a Tracker to each foot and one on the waist. This three-point inverse kinematics solution uses the combination of known ankle and hip positions gives a pretty accurate representation of the lower body with improved prediction accuracy, especially when combined with positional information present in the head and hands from the headset and controllers respectively.

As explained in the documentation, without tracking points on the knee, there are still unknowns with knee positioning, but this is largely solved thanks to common traits with human body movement; your thigh is usually pointing in the same direction as your foot when you are standing.

As the Trackers are wireless and lightweight, they can be securely attached with just a few straps, but it is recommended to use some kind of stiff panel (e.g. a square of cardboard) in order to improve tracking stability.

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Photo courtesy James Xiong / HTC

HTC and developers are still in the early stages of building out the Vive Tracker ecosystem, but later this year the company plans to open the device up to wider sale to businesses and consumers, beyond just developers.

SEE ALSO
How to Use the HTC Vive Tracker Without a Vive Headset
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The trial version of Microsoft’s Monster Truck Madness probably had something to do with it. And certainly the original Super Mario Kart and Gran Turismo. A car nut from an early age, Dominic was always drawn to racing games above all other genres. Now a seasoned driving simulation enthusiast, and former editor of Sim Racer magazine, Dominic has followed virtual reality developments with keen interest, as cockpit-based simulation is a perfect match for the technology. Conditions could hardly be more ideal, a scientist once said. Writing about simulators lead him to Road to VR, whose broad coverage of the industry revealed the bigger picture and limitless potential of the medium. Passionate about technology and a lifelong PC gamer, Dominic suffers from the ‘tweak for days’ PC gaming condition, where he plays the same section over and over at every possible combination of visual settings to find the right balance between fidelity and performance. Based within The Fens of Lincolnshire (it’s very flat), Dominic can sometimes be found marvelling at the real world’s ‘draw distance’, wishing virtual technologies would catch up.
  • Sam Illingworth

    Want! Not at £300 though :(

    • Rogue Transfer

      Yeah, I’m hoping one of the 500+ SteamVR partners will be producing cheaper, bespoke tracked peripherals using less sensors for feet & waist than the standard puck. Since most of the top puck sensors are blocked.

      Ignoring cost, the nice thing – now that someone found how simple it is to enable pucks without a headset(just set headset-required, from true to false in the SteamVR settings file) – is that even people with a mobile, FOVE or an Oculus Rift can get a Lighthouse(or two) and use the pucks for full body IK or other things too! (in theory, with a bit of simulated controller input to pass SteamVR setup)

  • Sponge Bob

    gotta be kidding

    now they want us to attach those big ugly trackers to every part of our bodies

    ridiculous concept

    how about tracking IR LEDs or reflective markers with IR cameras ?
    that’s what they do in motion picture industry

    • NooYawker

      Right?! They’re so ugly, because we all care how we look when we’re using our VR gear.

      • Sponge Bob

        ugly means too big and not well shaped for practical purposes

        • NooYawker

          Yea let’s use the camera based solution .. oh wait.. there isn’t one. So let’s theorize about how superior sensors using webcams are.

          • AnnoyedAnonymous

            VRcade/Studios?

    • jacobpederson

      This is not possible with the current Vive tech, the trackers are “seeing” their coordinates against a passive 3d map provided by the IR lasers. Oculus VR uses the type of system your suggesting, with external cameras that see lights attached to their hardware. However, Vive’s system has proven to be much more robust in large VR environments.

      • Sponge Bob

        “large” environments ?

        just how large ?

        cameras have no limit on distance – it all depends on camera ($$$) and the brightness of your LED

        e,g those guys claim the range of > 10m
        https://vrtracker.xyz/

        its larger area than HTC Vive can currently cover, correct ?

        PLUS, lighthouse DOES NOT scale at all (you can only have 2 in one area), whereas cameras do scale up easily with software

        • peteo

          >where as cameras do scale up easily with software HAHA tell that to all the people having issues with 4 cameras and not enough USB bandwidth.

          >lighthouse DOES NOT scale at all
          You DO NOT NEED MORE THAN 2 Lighthouses! They only send out 2 beams each and do not need to talk to any thing. The receivers take this info and use pretty simple calculations to find out where the object is in 3D space (similar to gps).
          You can have pretty much unlimited tracked objects in this volume. They could release a “professional” version of Light houses that have would have 1 or 2 more channels that would allow you to have 2 more lighthouses so you could make your volume bigger.

          Current distance suggestion is 5m but people have used them 10m apart and had no issues. Comes down to your play space.

        • Akiki

          >camera have no limit on distance
          >must spend $$$

          It’s the same “problem” with HTC vive if you got that way .. money can solve a lot of things ..

        • jacobpederson

          Camera’s can scale all they want to in the future;however, currently, my Rift can cover only about 1/2 the area my Vive does, and that is with two extra cameras and 1 extra usb 3 card.

        • Get Schwifty!

          Don’t waste your time – there is nothing harder than trying to educate those who refuse to see…

          Your discussion is about where it’s all headed and is correct ultimately – simple minds only grasp the here and now. The cameras do make more sense in the future, and yes, the Oculus sensors are actually a limited camera, albeit very low res which is part of their problem. Attached trackers are a nice convenient solution today, but are not very scaleable in the long run for many, many points of tracking. We’ll likely need a hybrid solution in the future for the best all around options to do more than just track for things like environmental mapping, etc.

          • NooYawker

            Well said. Especially since the goal is to get rid of external sensors all together no? Inside out tracking is the goal. And if there needs to be camera and lasers, sound microwaves sonar… who cares whatever it takes.

        • Raphael

          Actually it’s the laser based tracking that scales up much better. A passive camera is limited by IR led used on octopus. Saying a camera has no limit on distance is utter pish. By your statement we could say an octopus cam could see across a stadium.

          If you’re going to be tracking over larger distances (or smaller) nothing beats laser coverage.

          • NooYawker

            to a point then the lasers will blind everyone on the room lol. Jk

          • Raphael

            A minor consideration. How about using 3 lasers for color mixing and having the lighthouses produce lightshows. Has no one done this mod yet?

  • NooYawker

    More code computations more raw power needed. My brand new computer may not be enough for long.

    • Tomas Andersson

      Tracking requires almost no computational power. It’s rendering which is the issue.

      • NooYawker

        It’s not just tracking is it. I thought It’s predicting where your body should be according to where the trackers are. But then again I’m no expert, far from it.

        • Tomas Andersson

          No it’s not predicting it like that, this is nothing that takes any sort of significant computing power. Far from it.

  • Kyle Biggs

    Keep in mind that they are ‘big’ because they need to protrude away from whatever they’re mounted on in order to catch the tracking laser light. If these were the size of a stick of gum, they would be occluded much more often, causing tracking issues.

    And no, you aren’t expected to strap $2k of these all over your body. Developers are using these to learn how to implement more complex motion tracking in VR, and to develop game mechanics. It’s obvious to most of us that the average VR user isn’t going to use them like this, but developing systems to utilize more tracking points creates incentives for hardware developers to make more user-friendly products.

    Personally, I hope to see a smaller form-factor Vive tracker that uses IMUs and magnetic positioning to alleviate occlusion and make up for the smaller size, but I can deal with these suckers for developing software.

  • Jordude

    We’ve managed to play with consistent tracking with the lighthouses 32 feet apart as long as you wire them together. Size of the Vive cable is only thing limiting a huge playing area.

  • Well, cool. I still think that the future will be Kinect-like… but for the present this seems the most reliable solution

  • Will Von Wizzlepig

    Given that the kinect 1st gen trackers were pretty decent, and are now a dime a dozen… it would be nice if they could just plug into the wall-mounted Vive tracking units and cover the rest of the body tracking. Problem solved with only minor hardware mods and some cobbling together of already existing code.