The problem with Tennis games on the Wii

Discussion in 'Wii - Console and Game Discussions' started by Hooya, Jun 11, 2009.

Jun 11, 2009
  1. Hooya
    OP

    Member Hooya GBAtemp Advanced Maniac

    Joined:
    Aug 25, 2006
    Messages:
    1,878
    Location:
    Central Illinois
    Country:
    United States
    Reading all the reviews for the new tennis games that use the WM+ got me thinking: why can't they make a decent tennis game? Apparently TW10 is great and actually feels accurate, so it shouldn't be that hard, right?

    The problem is yaw.

    Yaw is the rotation of something parallel to the horizontal plane. You can think of yaw as the way a bottle is pointing when it's on it's side on a table for "spin the bottle". The trouble with the Wii remote is that it has NO way of detecting yaw positioning. There's no internal compass that says which way it's pointing, just if it's tilted either to the side or up/down.

    Essentially the Wii remote is always only operating in two dimensions: Y (tilt) and Z (rotation), but not X (yaw).

    Now, think about how what happens to the Wii remote when you swing it like a racket, parallel to the ground:
    If you're looking at a top down view of the player it's first this position: _ then this: / Then this: |
    All yaw determined.

    So I figure the way the developers are translating Wii movement to the game is by way of the part of Newton's law that states that an object at rest tends to stay at rest. When you move the remote it senses a movement, but because it's missing a way of detecting yaw it's got to guess at the yaw orientation based on other factors including momentum and G-forces. This is problematic to say the least.

    Golf works well because when you swing the Wii remote like a golf club you're altering other dimensions, especially on the Tilt axis.

    Back when the Wii first came out I saw a youtube video talking about ways to get around the yaw limitation of a Wii remote. Most of the time it's negligible because there is the IR sensor that can sort of take the place of yaw, but only if you're pointing it at the TV... not really helpful for a tennis game.

    Any thoughts? Think I'm right? Any reason to suspect that my hypothesis is incorrect?
     
  2. beegee7730

    Banned beegee7730 ITS PAAFEKUTO!

    Joined:
    Mar 31, 2009
    Messages:
    1,693
    Location:
    England
    Country:
    United Kingdom
    I agree with this, but when I saw E3 they had a Wii motion plus demo with a parachuter, and it looked like it measured Yaw.
     
  3. Ossot

    Member Ossot GBAtemp Fan

    Joined:
    Jun 7, 2009
    Messages:
    494
    Country:
    United States
    I could very well be wrong, but I was watching a 'dev diary' video for VT 09 and the guy states M+ has a gyroscope in it. Now i'm not exactly 100% read up on what a gyroscope is, but can't it detect any movement along any axis? Meaning a gyroscope can fully detect yaw?

    edit: Found the specs on the chip M+ uses. Looks like it does indeed detect along the X axis.

    http://www.invensense.com/products/idg_600.html
     
  4. alucard77

    Member alucard77 GBAtemp Fan

    Joined:
    Jul 20, 2006
    Messages:
    465
    Country:
    United States
    How about height? I think the WiiMote does a bad job of identifying hieght in a tennis game. In tennis, you can hit a shot that needs to be returned at shoulder hieght vs. hip height. The Wiimote really does a poor job of identifying how high or low you are holding it.

    The Wiisensor is not so great to tell it either.
     

Share This Page