WALK AND RUN CYCLES

How to Animate a Walk Cycle



The key to animating a walk cycle is to understand how the legs PUSH THE MASS of the body forward, and how the feet connect with the ground.
When we walk we move our MASS in four stages:
The front foot makes contact with the ground
The mass of the body falls on that foot and the leg bends, cushioning the fall
We then use the momentum to propel our mass forward again
One leg supports the body weight while the other passes forward for the next step.


This illustration shows one step - remember to animate the second leg!














The Key Frames




The animation presented here below is slower - this is a 24 frames walkcycle (for both legs) at 24 fps:The more forward it leans, the faster your character should walk.Look out for a common mistake - check each frame and make sure the body didn't get left behind... (maybe it doesn't want to go? :-)The best way to animate is to move the big mass first, and then the rest of the body.Which leg supports the weight in the frame I'm animating now?The answer will solve 90% of all your problems.Make sure the feet keep good contact with the ground - Don't let them slip.If a foot now supports the body weight, then IT CANNOT MOVE!Cool hah?SO when you animate - determine which foot supports the weight, and FREEZE it. Disable the tweens.Delete foot keyframes until you reach a frame when this foot must move again - and the other foot takes on the weight.As we walk, our legs push our bodies upward as well as forward, and we rise and fall with each step.The lowest part is the bounce, key frame #2, when the front leg receives the weight and bends under it. The highest part is the passing position, where we stand on one straight leg. (Green Passing Position break-down frame)


To animate a walking cycle, you need three key frames (1, 2 and 3 in the list above), and one breakdown position ( 4 ) the passing position.
Most walking cycles work best at 9 frames per step = 18 frame cycle for both feet.



The mass needs to be above the feet and slightly forward.
Whenever you get confused, ask yourself this:
This leads us to the second most important thing:
Keep your feet on the ground!
Here is the logic of it:
The body mass goes up and down




Different Walks




A formula.
Here are some things to consider:

For a Massive man - make slower steps and a deeper bounce (go lower on key #2).
Woman on high heels - small steps, almost no bounce, mass barely moves up and down.
Bugs Bunny style "double bounce" - add another dip in the passing stage. (Another #2, so to speak).
Play with the break down - especially the passing position - to give your character some character.An "Advancing Walk Cycle" vs. a "Moon-walk" cycle


In my experience it's best to animate a normal advancing double step first, and only when you're happy with it, "squeeze" the key frames in.
Mark the center of gravity with a guide line and cut and paste the character in each frame to this center.

The above formula is just that:
You need to modify it for your characters.
If you're creating a walk cycle animation for a game, you might want it to happen "on the spot".






How to Animate a Run Cycle




A run cycle has the same as basic animation principles - but with a lot more force.
Instead of just propelling our mass forward, we need to push it entirely off the ground.
These are the basic key frames for one step of a running cycle:










This illustration shows only one step - remember to animate the second leg!


This is running at 14 frames per step (one leg), at 24 fps.
When animating a character walking from the front we need to show:

The body MASS going up and down
The legs bending in perspective
The feet flipping
Mass


Moves up and down as it does in the side view.
If you wish to elaborate - show the hips swinging - the foot that's forward brings its side of the pelvis down.


Drawing legs in perspective


Most of the foreshortening happens to calf.
The thigh gets fore-shortened as well but unless your character brings its knees up very high - don't shorten the thighs too much.
Flipping the Feet


If you are animating Flash or After Effects Cut Outs, you have no choice - You need to draw the foot from three angles and switch between them as you animate:
Frontal view, flat
Raised up, showing the laces
Flipped, showing the underside.
It's not very convincing otherwise.
Stylize the walk


For different kinds of characters, play with
Step Width - men take wide strides (gee, I wonder why!), women walk in narrow steps.
For a stylized feminine walk - cross the legs over, the way runway models walk. Swing the hips!
Most people point their feet outward. We don't walk all that straight!
Remember that regular people barely lift their feet off the ground - it's a waste of energy to lift the knees higher than needed.
Threre's no need to drag the feet, but for a natural looking walk, don't lift feet and knees more than is absolutely necessary.
Modify these simple key frames to fit your character.