"The Physics of Ball Spin in Tennis, Topspin and Backspin" (471941)

Unity Engine
1

hi,

How to implement the physics of ball spin in a tennis with unity’s physics engine? As we know in real world physics a top spin ball has more power to travel towards a player after bouncing, while backspin/slice ball gets more fraction after bouncing.

How to simulate a natural ball spin like that in unity? I can’t get it done with rigidbody and addforce with torque force. Please help!

Thanks,

2

I am not big on Collisions and real world physics, but I do believe you can see where the point of contact was on the object. If the point of contact is dead on the “equator”, no top spin or back spin should occur. But if you hit above that line top spin should occur. The physics engine is pretty good, so I would think that it would happen naturally (the creation of top spin) but if not, if you can detect, if top spin is deserved, why not just increase rotation speed?

3

I have no problem with the creation of topspin/backspin. My major concern is how those spins affect the flying path and bounce of the tennis ball. I’ve also tried to modify the rotation manually as you mentioned, but so far I can’t observe a significant difference when spin is applied to a rigidbody. As in unity’s physics engine it looks like the rotation speed of the ball itself and the angular drug property never affects the ball’s actual movement. What’s wrong with it?

4

Not sure.
Can you, when ball hits ground, measure rotation speed and have that effect the bounce?

Just an idea, as i say i dont really know much about the physics engine.

5

Thanks renman. The method I currently using is change the ball’s physical material based on its spin type. e.g. modify the ball’s physical material with greater bounciness when it about to hit the court can simulate a topspin. But it’s not realistic and i’m looking for a better way to do it with the physics engine.