Q：Components cannot be separated
A：There must be a gap between the part and the part, and put them together to be one part.
Q：Turn on body is respondable, the components cannot operate on the normal track, it will flutter.
A：Because the interval between the solid and the solid cannot be 0, there must be gap.
Q：Turn on body is respondable for the track, the simulation will be very lag.
A：Turn it to collide with the ball.