Determining relative position is impossible without input from the user.
But it is very possible with input from the user. The user just holds the nunchuk out front with the remote right behind it then presses and holds a button. Then you simply pull back (like a slingshot) and when you are ready to realease the shot you release the button.
The remote can tell the direction and speed it is moving, so if it is told when it is at "the start" point(ie pressing down on the button) they just keep track of where it moves relative from that position. With that position they can tell force imparted based on elasticity of the "slingshot band", and they can get angle of release from its release position(ie let up on the button) relative to start position.
They have everything they need: An origin, all movements from the origin, and the wii-mote "knows" which way is down (providing necessary reference for angle of fire).
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| To Each Man, Responsibility |
