Determines the size of the bounce when the joint hits it's limit. Also known as restitution.
Additional resources: bounceMinVelocity.
The size of the new velocity after the bounce will be determined as:
newVelocity = currentVelocity * bounciness.
When opening an old project using the deprecated maxBounce and minBounce the new bounciness will be chosen as the maximum maxBounce and minBounce.