Bouncy Ball stops without enough force

Bouncy Ball stops without enough force

I am building a 3D Pong clone and want to implement a frictionless bouncing ball.
These are the steps i took:

Create a box in which the ball can bounce, consisting of standard cubic objects.
Create a ball using a spherical object
Add a Rigidbody to said ball (Mass: 1, Drag: 0, A.Drag: 0, no Gravity)
Add a bouncy Physics Material to the balls Sphere Collider (D.Friction: 0, S.Friction: 0, Bounciness: 1, Fraction Combine: min, Bounce Combine: max)
Add a script to the ball that adds force to the ball on start:

Script Snippet:
void Start() {
    this.getComponent().addForce(0, 0, 100);

When i play the scene, the ball will fly towards the wall and then stop. If i change the added force to (0,0,101) it works as intended. If i lower the mass of the ball and use the old force (0,0,100) it also works. But it will always stop at the wall, if the added force is <= mass*100.
What am i missing?


Answer 1:

A guy on my development team actually found the source of the problem:

Unity has an internal Bounce-Threshold. If the velocity towards one axis does not reach this Threshold the velocity will be set to 0. This is a nice feature for normal game physics, as bouncing objects will come to a rest faster, but you can't build a perfect bouncing ball without lowering the value.

You can find the Bounce Threshold in the Physics Manager ( Edit > Project Settings > Physics ).