tfHelicopter.setTranslation(new Vector3f(0.0f,platformSize+cabinRadius,0.0f));
//The transformation group for the helicopter.
TransformGroup tgHelicopter = new TransformGroup(tfHelicopter);
tgHelicopter.addChild(tgCabin);
tgHelicopter.addChild(tgRotor);
tgHelicopter.addChild(tgTail);
//*** The helicopter and the platform are joint together in one ***
//*** transformation group in order to place them together ***