Spatial Offsets
3D animators will be familiar with the idea that everyobject (or layer) has a pivot point. In After Effects, there
are two fundamental ways to make a layer pivot around a
different location: change the layer’s own Anchor Point
setting, or parent it to another layer.
After Effects is generally designed to preserve the appearance
of the composition when you are merely setting up
animation, toggling 3D on, and so forth. Therefore editing
an anchor point position with the Pan Behind tool triggers
the inverse offset to the Position property. Parent a layer to
another layer and the child layer maintains its relative position
until you further animate either of them.
It’s typically best to set up your offsets and hierarchy before
animating, although this section shows how to go about
changing your mind once keyframes are in place. The
Option key is key to all options.
