public void AddToWorld()
{
body = world.CreateBody(bodyDef);
foreach (ShapeDef shape in shapes)
body.CreateShape(shape);
body.SetMassFromShapes();
body.SetUserData(this);
foreach (Controller controller in controllers)
{
controller.AddBody(body);
world.AddController(controller);
}
foreach (PhysicsObject child in children)
child.AddToWorld();
}