How to make a perfect elastic collision.

Hi, I am beginner.
I want to realize perfect elastic collision.

So, I set my sphere’s material bouncy.

In the bouncy inspector, I set the value of bounciness 1 to make a perfect elastic collision.

Also, all friction value is 0.

However, there is a problem.

In the perfect elastic collision, the height of the sphere is constant in the constant gravity,
but my sphere’s height is more more higher.

What’s my problem???

Please Help me.

You have to conserve angular momentum before and after collision.You can follow these videos for better understanding BallBricker - The GamePlay - YouTube .Soon a blog will be written on it.