Frame Blending

Frame Blending

Suppose you don’t use a stretch value that factors evenly
into 100% (such as 50% or 200%); footage is likely to lurch
in a distracting, inelegant fashion. Enable Frame Blending
for the layer and the composition, and After Effects averages
the adjacent frames together to create a new image
on frames that fall in between the source frames. This

also works when you’re adding footage to a comp with a
mismatched frame rate. There are two modes:
. Frame Mix mode overlays adjoining frames, essentially
blurring them together.
. Pixel Motion mode uses optical fl ow techniques to
track the motion of actual pixels from frame to frame,
creating new frames that are something like a morph of
the adjoining frames.
Confusingly, the icons for these modes are the same as
Draft and Best layer quality, respectively (Figure 2.20), yet
there are cases where Frame Mix may be preferable instead
of merely quicker to render. Pixel Motion can often appear
too blurry, too distorted, or contain too many noticeable
frame artifacts, in which case you can move back to Frame
Mix, or move up to the Timewarp effect, with greater control
of the same technology (later in this chapter).