written and performed by two educators,

Brad Voytek and Tim Verstynen.

These two scientists used a drooling,

hag-faced, animated zombie

as a mechanism to model

the symptoms and medical diagnosis process

for various neurological conditions.

For example, they spent time debating

whether the zombie's stiff gait

was caused by basal ganglia damage,

like that in Parkinson's patients,

or by severe damage to the cerebellum,

which can cause ataxia.

In each Lesson, Brad and Tim certainly showed us

how the walking dead can help us

understand neuroscience,

but how can the walking dead

help us understand animation?

Or, more simply put,

how did this one-eyed, decaying,

and very much dead pile of pixels walk?

Puppet animation is a relatively quick solution

to creating 2-D animation of a hand-drawn character.

Since the character does not need

to be drawn over and over again,

it can be animated by moving each element individually.

Aside from their portrayal

in a few great modern zombie flicks,

these concocted carcasses are generally known

for limited, stiff movements.

Their traditional stride is perfect

for puppet-style animation.

When designing a 2-D zombie puppet,

or any other type of puppet,

it is important to find a design

that is both fun and functional in a flat environment.

For example, you might not want to puppetize, say,

Julie Andrews in the "Sound of Music"

as she spins in circles.

We used rotoscoping for her,

but that's another lesson.

Always begin by sketching and designing your puppet

in a neutral pose

like this.

This will allow it to easily transition

into and out of a variety of extreme positions.

Once a character transitions

from concept stetches

to final design,

the next step is to break up the pieces

in order to assemble a puppet,

keeping in mind that each element

needs to have an appropriate amount of overlap

so that the Zombie can bend at his joints.

An understanding of anatomy is an integral part

of designing any 2-D or 3-D animated character

that needs to move realistically

in the context of its environment.

Regardless of the number of dimensions your character has,

you'll need to create a skeleton,

which in animation terms is known as a rig.

Once the rig is finalized

and the range of motion is determined,

the next step is to choose anchor points.

Each piece of artwork has its own anchor point,

which essentially assigns the limb a hinge,

which in this case is a joint.

Next, line the artwork up

so that the anchor point for the forearm-elbow

sits on the upper arm's elbow area.

Once all the artwork is in place,

you can use an expression script

that creates links between the body parts.

In this case, we used the expressions

provided in After Effects.

By parenting one layer to another,

you could teach the forearm

to follow the upper arm

and the hand to follow the forearm.

This is what's called forward kinematics.

The alternative is inverse kinematics,

in which a separate set of scripts control the motions.

In this case, a controller is attached

to the anchor point of the hand.

The animator then uses the controller

to position the hand.

The scripts will then use an algorithm

to make sure that the rest of the arm

and body follows along.

Once the character is rigged,

we can start animating.

Often times, puppet animation is done

as straight-ahead action,

which means moving a character frame-by-frame

from beginning to end.

Another approach is pose-to-pose animation,

which involves choosing your key poses first,

and then filling in the intervals,

or in-betweens, later.

Regardless of the method of motion,

it's important to think of your 2-D puppet

as a piece of paper.

It can move across a surface

in a variety of poses,

but it cannot move in perspective.

If your character needs to turn its head,

then you will need to create additional art.

We created three different zombie heads

and six different hands

to achieve different movements and angles

that the neutral pose couldn't accommodate.

You can recreate almost everything

you've seen in this Lesson

with a pen, paper, and a camera.

The method is called cut-out animation,

and it was around well before the age of software.

To create a stumbling 2-D zombie,

or a speeding narwhal,

or even an abstract character

with some semblance of joints,

simply print,

cut,

and fasten your character's limbs together

in a neutral pose.

You can use fasteners,

string,

or even just place and move them each time.

All the same rules and theories

that we use in the computer

apply to cut-out animation,

except under the camera,

the only way to animate is straight ahead.