Car Trailer Physics

[Pazil]

You can do it using IK (seems what they've done). All IK is (I was surprised how simple it was) is setting a distance between 2 nodes, and then when you move one, you move the other so that the distance requirement is met. The rear of the car would be one node, and then the rear of the trailer would be the other, and then each frame you do:

var dx:Number = car_rear.x - trailer_rear.x;
var dy:Number = car_rear.y - trailer_rear.y;
var rads:Number = Math.atan2( dy, dx);
trailer_rear.x = car_rear.x + Math.cos( rads) * distance;
trailer_rear.y = car_rear.y + Math.sin( rads) * distance;
trailer_rear.rotation = 180/Math.PI * rads;

The only thing you need to define before hand is the distance variable, which will be the distance you want to keep between the car and trailer.

P.