question: public void swapChildren ( int index1 , int index2 ) { Spatial c2 = children . get ( index2 ) ; Spatial c1 = children . remove ( index1 ) ; children . add ( index1 , c2 ) ; children . remove ( index2 ) ; children . add ( index2 , c1 ) ; }
target:  More efficient than e.g detaching and attaching as no updates are needed.