Hollywood FX is a true 3D animation system and uses object hierarchies to create complex multi-object movements. An object hierarchy is when one object is the child of another object. When the parent object moves, the child object moves with it. In the FX Tree panel you will often see an objectâ€™s icon indented directly below another object. This indicates that the indented object is the child of the object above it. You can change the hierarchy by changing the parent object for any object.
An object hierarchy in the Scroll2 FX. The Scroll Parent Null is an invisible null object that is used to control the movement of all of the pieces of the wooden scroll (Stick, Stick, and Scroll).