Gesture controlling a $20k robotic arm.

I wrote a program that lets you control a robotic arm using hand gestures captured via a camera. You can make it follow your hand position and orientation. I remember it also recognized a few specific gestures to trigger how many degrees of freedom the arm should move in.

A lot of matrix math to get it work right. I remember I accidentally flipped a sign in one of the axises and the arm came crashing into the table - could have been expensive, but got away with it that time.