public void update(){
  if (amplitude > 0) {
    long elapsed=System.currentTimeMillis() - timestamp;
    double delta=amplitude * Math.exp(-elapsed / timeConstant);
    if (Math.abs(delta) > 0.5) {
      viewpointNode.drag(lastDx * delta,lastDy * delta);
    }
 else {
      amplitude=0;
      updateLookAt();
    }
  }
}

public void update ( ) { if ( amplitude > 0 ) { long elapsed = System . currentTimeMillis ( ) - timestamp ; double delta = amplitude * Math . exp ( - elapsed / timeConstant ) ; if ( Math . abs ( delta ) > 0.5 ) { viewpointNode . drag ( lastDx * delta , lastDy * delta ) ; } else { amplitude = 0 ; updateLookAt ( ) ; } } }
update the kinetic scrolling
