3D 객체를 애니메이션으로 컨트롤해서 돌리는법좀 알려주세요;;

Storyboard sb = new Storyboard();

                                    Rotation3DAnimation rani = new Rotation3DAnimation(new AxisAngleRotation3D(new Vector3D(0, 1, 0), 0),
                                        new AxisAngleRotation3D(new Vector3D(0, 1, 0), 45), new Duration(TimeSpan.FromSeconds(0.5)));

                                    Storyboard.SetTargetName(rani, "one_ring");
                                    Storyboard.SetTargetProperty(rani, new PropertyPath("(Visual3D.Transform).(Transform3DGroup.Children)[0].(RotateTransform3D.Rotation)"));

                                    sb.Children.Add(rani);
                                    sb.SpeedRatio = 1;
                                    sb.Begin();

이렇게 했는데;;흠 에러나네요;;