Search Unity

VR tips for ski jumping application

Discussion in 'AR/VR (XR) Discussion' started by Staur, Feb 6, 2015.

  1. Staur

    Staur

    Joined:
    Feb 6, 2015
    Posts:
    8
    Hi there,

    I am a masters student currently working on a VR ski jumping application. I am relatively new to Unity and Virtual reality.
    I have created a raw prototype which you can find here: https://www.dropbox.com/sh/luoj1x57nmzf4te/AACNC3fksvTNO38uiRVw47d9a?dl=0 (2D) and https://www.dropbox.com/sh/db2bkhkmxsc1tz5/AADAGjIoX4o24JQZSVYQgE3oa?dl=0 (3D)

    An important factor in a ski jump is the angle of attack, the angle between the ski jumpers body and the velocity. My plan was to use Kinect to measure the angle of attack like this: http://gyazo.com/e5736a3fd62e8c455821f2828a99ac4a
    .
    I am using the Zigfu ZDK to integrate with the Kinect, but the skeleton tracker seems to be struggling when I am leaning forward or/and having the Kinect tracking me from the side.

    So my question to is if you have any suggestions to how I could use the Kinect to measure this angle, or other methods/equipment I can use to measure the angle of attack.

    Thanks,
    Staur
     
    Last edited: Feb 6, 2015
  2. El Maxo

    El Maxo

    Joined:
    May 23, 2013
    Posts:
    177
    Just a quick idea, have you thought about using the wii balance board
     
  3. mgear

    mgear

    Joined:
    Aug 3, 2010
    Posts:
    9,447
    I've tested balance board+unity while ago, had problems with:
    - Uses batteries
    - Doesnt automatically connect bluetooth if app/pc is closed/restarted
    - Calibration is sometimes off (that might had been because of low batteries though)
     
  4. Staur

    Staur

    Joined:
    Feb 6, 2015
    Posts:
    8
    Hi,
    Yeah, i am planning to use the Wii balance board for the timing of the jump. But as far as I know it cannot be used for measuring the angle of attack. I am considering using optical tracking to determine the angle. Do you have any experience with this?
     
  5. mgear

    mgear

    Joined:
    Aug 3, 2010
    Posts:
    9,447
    If player is "leaning" forward, could see more weight on the front weight sensors,
    but of course it cannot see if you are actually leaning or not..

    Better having the kinect at front and then trying to detect leaning from there.
     
  6. Staur

    Staur

    Joined:
    Feb 6, 2015
    Posts:
    8
    Yeah that could work. But I aim to create an experience where the player have to use his body in a similar fashion to a real ski jump. It seems to me that the balance board technique is not "realistic enough". The end goal is to create an application that could be used by professional athletes in a training situation.

    The Kinect seems to have problems reconstructing a forward leaning skeleton even when the Kinect is at the front.

    But just now I got an idea! It evolves around using head positions as a reference with the Kinect at the front. I'll test it out right now!

    Thanks,
    Staur
     
  7. Staur

    Staur

    Joined:
    Feb 6, 2015
    Posts:
    8
    Hi,

    I think i might end up ditching the Kinect altoghether replacing it with a Wiimote attached to the players body. It seems to be working pretty well. But there is a problem with the Wiimote disconnecting after one test in the editor. Then I have to restart the editor to get it to work again. Have any of you experienced similar problems?

    The Wiimote is connected with Bluetooth, and I am using the UniWii plugin for unity,
     
  8. mgear

    mgear

    Joined:
    Aug 3, 2010
    Posts:
    9,447
  9. El Maxo

    El Maxo

    Joined:
    May 23, 2013
    Posts:
    177
    I know it may sound silly, but would you not have a issue with balance, when the person is leaning?
     
  10. El Maxo

    El Maxo

    Joined:
    May 23, 2013
    Posts:
    177
    so for a true VR experience I personally think a key point is about immersion, otherwise whats the point. pro ski jumper lean at crzy angles due to wind resistance, have you thought about the player leaning, there balance, and what there lean angles are( is it 1 for 1. I havnt had time to look at your project in to much detail, but it is very intesting to me, have you got plans on using the rift in it, I have some ideas if you would like to know more
     
  11. JDMulti

    JDMulti

    Joined:
    Jan 4, 2012
    Posts:
    384
    Just an idea, but how about a space hopper with on top a thick wooden board and on the corners a leg that's about 5 / 10cm shorter. Then in the middle of the board, cut a hole where a Wii controller fits in.

    Now with unity you can connect to the Wii controller and get the balance of the user. The user will lie on top of the board with the toes of his feet attached to the ground. With this he can lean forwards until the legs of the board hit the ground or lean left, right and backwards. The duration of the leaning will be the speed of which the user will move in the game.

    With some engineering you can make a really nice setup and use it for flight simulations and so on. You could ofcourse use Kinetic and use all kind of nice recognition software, but a simple gyrometer would make it easier for development.
    Good stuff to make this kind of leaning controller yourself with a Wii controller would be:
     
  12. Staur

    Staur

    Joined:
    Feb 6, 2015
    Posts:
    8
    You raise some important questions here El Maxo. When the ski jumpers are in the flying phase he is almost "falling forward" with his body being almost horizontal (about 10-11 degrees on the horizontal axis). To me this seems to difficult to reproduce in a VR application. So some kind of simplifications is needed. My current solution is having a Wii controller attached to to the players body, measuring the angle of the torso on the x-axis. With this setup you should not have an issue with balance, and the leaning angles will be roughly 1-1. I have tried to illustrate my setup with my fantastic paint skills here:

    https://www.dropbox.com/s/atbsm6mxew0yiml/skijumpSetup.png?dl=0

    I am already using the rift for this application. I am also planning to use the Wii Balance Board for the "jumping"in the application, but I have not looked very much into that yet.

    As I mentioned in the first post this I am new to game development and VR, so I would love to hear some of your ideas.
     
  13. Staur

    Staur

    Joined:
    Feb 6, 2015
    Posts:
    8
    I must say I really liked your idea JDMulti! That would be an excellent way to solve the flying phase of the application. The downside with it is that the player would have to be lying on the floor throughout the whole jump, and I want the player to be doing a real jump in the application. I have been in meetings with some coaches from my national ski jumping team, and they say that the training value (for athletes) from such an application would first and foremost be practicing on the timing of the jump. So its kind of important that the jump is also feeling realistic for the player.
    The flying phase will be to simplified to have any real value for professional athletes.
     
  14. JDMulti

    JDMulti

    Joined:
    Jan 4, 2012
    Posts:
    384
    Yeah I was confused by the Topic title. Thought is was about sky jumping, but it's jumping off a ramp with skies after I saw your application.

    Can't you do something with a plate and touch sensitivity? Like there is a plate with a gamepad under it, when you jump, the button is released, when you land it's getting hit. Ofcourse make it so that the gamepad won't get crushed ;) Or use the Wii controller to sense acceleration which should be possible when you jump.
     
  15. Staur

    Staur

    Joined:
    Feb 6, 2015
    Posts:
    8
    I understand that the topic title might be confusing ;) Those are both good ideas! It would be nice to just use the Wiicontroller, as I wouldn't have to purchase more equipment ;) I have also been thinking that it would have been cool to have some kind of a force plate, which enables you to also measure the force of the jump. I was thinking about trying the Wii balance board for that, but it is maybe to fragile?
     
  16. El Maxo

    El Maxo

    Joined:
    May 23, 2013
    Posts:
    177
    I have been developing with the rift now for a few months and one issue that has come across with a lot of people is motion sickness/dizzness and losing track of orientation (not a issue for what I do but with yours will be) An Idea for you, witch could help with balance and orientation is "ski poles" these could be "fitted" to floor so the player has something they can learn agesnt, thus letting them go to more extreme angles