[Box2D] соединение двух тел

[provigator]

создаю 2 тела

bodyDef=new b2BodyDef()
bodyDef.position.Set(c1.x/30, c1.y/30)			
boxDef=new b2PolygonDef()
boxDef.SetAsBox((c1.width)/30/2, (c1.height)/30/2)
boxDef.density=1.5
boxDef.friction=0.5
boxDef.restitution=0.2
bodyDef.userData=c1
body=m_world.CreateBody(bodyDef)
body.CreateShape(boxDef)
body.SetMassFromShapes()
 
bodyDef=new b2BodyDef()
bodyDef.position.Set(c2.x/30, c2.y/30)			
boxDef=new b2PolygonDef()
boxDef.SetAsBox((c2.width)/30/2, (c2.height)/30/2)
boxDef.density=1.5
boxDef.friction=0.5
boxDef.restitution=0.2
bodyDef.userData=c2
body=m_world.CreateBody(bodyDef)
body.CreateShape(boxDef)
body.SetMassFromShapes()

как соединить эти тела?
соединение должно быть жестким
версия 2.0.2