This property how elastic
Attachment|Attachments connected by a
TorsionSpringConstraint are when they reach the end of the range specified by
true. The value defaults to 0 and can be any floating number within the range [0, 1].
torsionSpring.Restitution = 0
What is restitution
Restitution determines the damping effect that the constraint applies when it reaches its limits.
Imagine you release a ball from some distance and it hits the ground. If the restitution of the surface is 1 then the ball will return to its original height (no energy is damped). If the restitution is 0 the ball will stick to the ground (all the energy is lost). Similarly, automobiles rely on damping for shock absorption as do some “slow-close” doors.
All the values between 0 and 1 will simulate something between these to extreme cases.