CookKeyframe
One point on a curve. Drag it in time and value, and pull its handles to ease in and out.
A CookKeyframe sits under a CookTrack. Position is its time and value, and LeftTangent and RightTangent are its two handles, relative to Position. Between two keys a Bezier track follows one cubic curve, from the left key's right handle to the right key's left handle; before the first key and after the last the value holds flat. Move keys in the Cook window, and shape them and their handles in the Graph Editor.
