In my Java2D simulation, I have a disc which, when it bounces off the boundary of a 2D region, begins to rotate, as if it had gotten some spin from the wall.
I'm having trouble relating the collision vectors and the angular velocity of the spin that should result.
How should I approach this?
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and so their direction doesn't have much meaning. (Consequently, crossing them with something wouldn't do anything very interesting.) \$\endgroup\$