Here’s a video of DIY motion-sensing cue-ball video game from back in 1990! That’s almost 20 years ago and way before Nintendo Wii ever became popular, nevermind we didn’t have 32-bit processors for video games then.
the middle section of the video reveals the trick behind it all, and it turns out to be surprisingly simple. No complex sensors or computer vision algorithms; the ball’s speed and direction are calculated by an 8-bit processor and a clever arrangement of four infrared emitter/detector pairs.
video://www.youtube.com/watch?v=2Wc_DXGe2fQ
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