@Override
    public void updateLogicalState(float tpf) {
        super.updateLogicalState(tpf);
        lastTpf = tpf;
    }
Set the audio node as positional.
The position, velocity, and distance parameters affect positional
audio nodes. Set to false if the audio node should play in "headspace".

@param positional True if the audio node should be positional, otherwise
false if it should be headspace.
jme3-core/src/main/java/com/jme3/audio/AudioNode.java