Apple Shake 4 - Manual (Page 780)

780 Chapter 26 Transformations, Motion Blur, and AutoAlign
The result is inaccurate when motion blur is applied. This is because the SpinWheel
node applies the blur for the turning wheel, and then three nodes later, the MoveCar
node applies the blur to the already-blurred wheels. Instead of the individual paths of
the color dots on the wheels, the result is a horizontal smear.
The following image shows the WheelsOverCar node immediately before the entire car
is panned. The result is bad because the wheels are blurred without consideration of
the forward momentum added in a later node.
To correct this, it is more efficient to apply three Move2D nodes to pan the three
elements separately, and then composite them together. In the following tree, the
MoveCar1, MoveCar2, and MoveCar3 nodes are identical, and MoveCar2 and MoveCar3
are clones of MoveCar1.