BUFFER CURVES

in the Graph Editor

As you moves keys of an animation and change the shape of the curve in the graph editor, you may want to see a trace of the curve's change; use Buffer Curves.

WHY USE THIS? to see where you're going and where you've been while moving curves/keys. helps with precision changes, and visulizes control!

(below left) is the result of selecting a Curve>Buffer Curve Snapshot (or simply hit the menu icon ) at the top of the GE

(below right) is the result of selecting a Curve>Swap Buffer Curve (or simply hit the menu icon ) at the top of the GE

Buffer Curves appear grayed-out or templated versions of the other curve..

Again, you won't see anything unless you go to View>Show Buffer Curves, in the GE