MapViewでpinが落ちてくるアニメーション

gistfile1.m

// これを適当なメソッドにして、CustomAnnotationViewにセットし、MKMapViewDelegateのmapView:didAddAnnotationViews
// でそのメソッドを呼び出すか、CustomAnnoationViewのdidMoveToSuperviewメソッドにセットする。

  CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];
  animation.duration = 0.4;
  animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
  animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DMakeTranslation(0, -400, 0)];
  animation.toValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
  
  CABasicAnimation *animation2 = [CABasicAnimation animationWithKeyPath:@"transform"];
  animation2.duration = 0.10;
  animation2.beginTime = animation.duration;
  animation2.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
  animation2.toValue = [NSValue valueWithCATransform3D:CATransform3DScale(CATransform3DMakeTranslation(0, self.layer.frame.size.height*kDropCompressAmount, 0), 1.0, 1.0-kDropCompressAmount, 1.0)];
  animation2.fillMode = kCAFillModeForwards;
  
  CABasicAnimation *animation3 = [CABasicAnimation animationWithKeyPath:@"transform"];
  animation3.duration = 0.15;
  animation3.beginTime = animation.duration+animation2.duration;
  animation3.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
  animation3.toValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
  animation3.fillMode = kCAFillModeForwards;
  
  CAAnimationGroup *group = [CAAnimationGroup animation];
  group.animations = [NSArray arrayWithObjects:animation, animation2, animation3, nil];
  group.duration = animation.duration+animation2.duration+animation3.duration;
  group.fillMode = kCAFillModeForwards;
  
  [self.layer addAnimation:group forKey:nil];

http://stackoverflow.com/questions/1857160/how-can-i-create-a-custom-pin-drop-animation-using-mkannotationview