Simple tracking in 3D space

[kylemcdonald] has posted this how to build a simple 3D tracking interface. Using 6 resisters, some wire, aluminum foil, an Arduino, and a cardboard box, he was able to do 3D capacitive sensing. Coupling that with Processing, he was able to overlay an interface using augmented reality. The video above shows a 3D tic tac toe application. While it seems less than perfect, its pretty amazing for how simple it is.

Seen anything similar to this out there? What applications would be fun with this?


  1. mike says:

    3d tic tac toe……..sweet. Thats going to be the next big craze like the rubix cube or sudoku.

  2. Bjonnh says:

    That’s an hack! :)

    Is there a way to create a 3d radio field like that ? (may allow multiple devices and maybe more precise detection).

    But that’s really fine!!!

  3. You could do this with two wiiMotes and a single LED or with one wiiMote and two LEDs. Shouldn’t be too hard.

  4. andrew says:

    Saw this through the instructables RSS feed yesterday; I was surprised at the accuracy of this setup. He also claims to be able to work in an 18 cu. in “arena” with this setup.

  5. “Is there a way to create a 3d radio field like that” I’m not sure I understand what you mean by “3d radio field” — do you mean adding more sensors, or…?

    “Thats going to be the next big craze” 3^3 is about as boring as 3^2, actually… lots of defense and not much strategy (I played it for a bit with a friend yesterday). Not until you get to 4^3 is it good (i.e., Qubic).

    Also, I wasn’t clear, but the compositing was done after the fact. I was going to put the “real” and “virtual” videos next to each other but thought it would be easier to watch like this. Though, with the various webcam libraries available for Processing, it would be a

  6. pascal says:

    a friend once built a robot, that would play 3D-Connect Four against a human, by stacking red and blue wooden blocks.
    Great fun, actually, and everyone looses when playing the first time. And some also on the second or third time…

  7. gally says:

    Surprisingly accurate.

  8. @5: 18 cu. in must be a typo — that’d be 2.5 inches on each side! I do have a bigger box that’s 18″ on each side though.

  9. joel says:

    If I were re-modeling a family room (or building a home sound studio), I’d put chickenwire under the drywall of two walls & the ceiling to do larger-scale capture.

  10. Pro_Digity says:

    Quite awesome how he managed to pull it off considering the parts he used,
    I’m hoping that he’ll manage to make it a bit more accurate though.


  11. localroger says:

    That is pretty cool considering the hardware. I bet if you used smoother/flatter plates (baking pans maybe) and instead of a hand, which is only approximately spherical, maybe a wand with a one inch diameter capacity probe, insulated handle, and very thin or shielded sense wire, you could probably get the resolution to under a centimeter with the same electronics.

  12. Schoolmarm says:

    Caleb, dude, check yer spelling. Two many “e”s in resist.. res.. the thing wot resists.

  13. Baggins says:

    You spelt resistor wrong.

  14. threepointone says:

    I love that game. Especially if I’m first, and the other guy has never played it before. For those of you who haven’t realized it, the first person always wins if you know what you’re doing =)

  15. threepointone says:

    oh and btw the way you play 3d tic-tac-toe on paper is to break it down into three individual 2D tic-tac-toe grids, and figure out the rest. The way you win first is pretty simple–take the very center piece, and it should be pretty damn obvious at that point how to win in 3-4 of (your) moves.

    It’s an electric field, not a radio field (whatever the hell that is). Capacitive sensors have amazing resolution, if you design them properly (your digital calipers use capacitve sensing–if you took it apart the sensor is basically a single PCB with the approrpriate pattern), and they’re really cheap. The only thing limiting accuracy with this is probably the shape of your hand/fist.

  16. Tony says:

    Good Hack dudes, nice. I’ll have to try out playing with capacitors like that….

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