So I have a bit of my map which is in space. The cart goes through an area which has lower than normal gravity and begins to float. As it stands right now, if the cart is not being pushed, it floats there, perfectly still, looking really unnatural. Is there a way to make it appear to be "bobbing" up and down? I've attempted 2 methods: Parent the Payload's path_tracks to a func_tracktrain that has the desired movement effect. This caused the Payload to do a 180 and fly off into a wall for no reason (rotating the tracks and the train did nothing). Parent the Payload prop to a func_movelinear which then is parented to the Payload's actual train. When the Payload crosses into space, the movelinear begins to move up and down. The Payload did the same thing as it did the first time, but in a different direction. Does anyone else have a solution?