timelinefx:timelinefx.tlGameObject.SetCollisionCircle
Method SetCollisionCircle:Void( x:Float, y:Float, r:Float, layer:Int=0 )
Set the dimensions of the objects collision circle
This will create a new circle collision with the given radius and set the collision type of the object to tlCIRCLE_COLLISION,
removing the current one from the world quadtree if it's in there. Set the layer to put the object on a specific collision layer.