Frame-by-frame animation changes the contents of the Stage in every frame. It is best suited to complex animation in which an image changes in every frame instead of simply moving across the Stage. Frame-by-frame animation increases file size more rapidly than tweened animation. In frame-by-frame animation, Animate stores the values for each complete frame.
To create a frame-by-frame animation, define each frame as a keyframe and create a different image for each frame. Each new keyframe initially contains the same contents as the keyframe preceding it, so you can modify the frames in the animation incrementally.
You can convert a classic tween or a motiontween span to frame-by-frame animation. In frame-by-frame animation,each frame contains separate keyframes (not property keyframes)which each contains separate instances of the animated symbol. Frame-by-frameanimation does not contain interpolated property values.
Usually, one frame of the animation sequence at a time appears on the Stage. To help draw, position and edit frame-by-frame animations, onion skinning provides reference by displaying contents of the previous and the following frames on the stage. The frame under the playhead appears in full color and apply color and alpha to differentiate between past and future frames.