I believe I have found a bug in the engine.
Take a look a this playground: https://www.babylonjs-playground.com/#BEFOO#347
Its just a simple scene, a ball and plane with physics.
press space. the ball comes at the camera, right?
Well, no. after it goes past, when space is pressed the impulses will ALWAYS be applied to the original impulse direction. It NEVER adjusts.
If anyone can try to fix this that would be GREAT!