Legs Jump

This is where the series turns into character animation. Up to now the object has been acted upon. From here it pushes against the ground under its own power, and that changes what the animator is responsible for.

What the video covers

Working through a jump with a legged rig: the foot positions and how contact is established and released, which parts lead and which follow, anticipation before the launch, the centre of gravity through the air, and the motion path the body travels along. Follow through, overlapping action and easing are all still running underneath, and the in-between work from the hammer applies directly.

Why the jump is the right first body mechanics exercise

It has a clear beginning, middle and end. Anticipation, launch, air, landing, recovery. Each phase has a job, which makes it diagnosable when one of them is not working.

The centre of gravity becomes visible. Once a body leaves the ground its mass follows a path it cannot renegotiate. Everything the character does in the air happens around that path, and understanding this early prevents a great deal of floating later.

Anticipation is proportional. A bigger jump needs a deeper crouch. The audience reads how high the character is going before they leave, from the preparation alone.

Contact is a contract. A planted foot does not slide. Not slightly, not for a frame. The floor is the one thing the viewer knows is not moving.

What to watch for

• Where the weight is. At any moment, which foot is carrying the body? Ambiguity here is why jumps float.
• The motion path. Check the arc of the hips through the air. It should be a clean parabola.
• Leading and following. The hips lead, the chest answers, the head arrives late. The chain from the pendulum still applies.
• The landing absorbs. Joints bend to take the load. A character who lands and immediately holds still reads as weightless.

Next: Heavy Lift, which adds a second mass to the problem.