Unity how to calculate the angle of the ball bouncing off the wall?

Question

C++ / C#

I'm making a simple 2D pong game (I think everyone knows what it looks like), I need to calculate the angle of the ball's rebound when it hits a wall (or racket), does anyone know the formula?

Answer 1

if the relative position of the walls is parallel to the coordinate axes (i.e., either a vertical or horizontal obstacle), then when it hits a horizontal wall, the speed along Y changes to the opposite (the sign changes) and does not change along X, but with a horizontal wall, on the contrary, along Y does not change, but X changes the sign to the opposite (multiply by -1)
if the obstacles have an arbitrary angle, then ... you can see the formulas here

Answer 2

https://docs.unity3d.com/ScriptReference/Vector3.R...