Hammer Strike
A weighted swing, and the first exercise built around in-betweens: what happens between the poses, and how easing decides it.
The hammer is where the series stops being about single ideas and starts combining them. A strike needs arcs, easing, overlap and follow through all at once, and it punishes any one of them being absent.
What the video covers
Building the swing from its key poses, then working the in-betweens: the frames that decide whether the hammer feels heavy or weightless. Ease in and ease out are introduced properly here, along with the follow through after impact and the arc the head travels along.
Why in-betweens are the subject
The poses are not the animation. Two identical sets of extremes can produce completely different results depending on what happens between them. This is the first exercise where that becomes undeniable, because a hammer that travels evenly between its poses reads as weightless no matter how good those poses are.
Easing is a description of force. Slow into a pose means something is decelerating; fast out of it means something is being driven. Applying easing uniformly because it looks smoother is how animation ends up feeling like syrup.
Arcs are physics. The head is on the end of a lever, so its path is a curve. Checking that curve is the single most useful diagnostic available on this shot.
Impact is not the end. Force has to go somewhere. The hammer rebounds and the handle answers, and an animation that stops dead on contact tells the audience the hammer weighs nothing.
What to watch for
- The head leads, the handle follows. Animating from the handle produces something weightless.
- Speed varies enormously. Slowest through the wind-up, fastest just before impact, then an abrupt stop and a slower recovery.
- Track the arc. Turn on a motion trail and check the head's path is clean throughout.
- Recoil. If nothing happens after contact, the weight established by the wind-up is thrown away.
Next: Legs Jump, the first body mechanics exercise.