Animation Advanced Action Animating - Movement Detail
GCC Academy
Hello, everyone
I'm Ji-Won Kang, your instructor for the Action Drawing course
Action refers to movement
When actions are connected, they create a situation
when context is added to that situation, it forms a story
In drawing, action enhances the sense of liveliness in an expression
and serves as a medium to convey deeper narratives
In this Action Drawing session, we will focus on movement
and explore various ways to capture it from different perspectives
This course focuses on drawing
to create visuals suited for animation
Therefore, we will concentrate on drawing skills
closely linked to animation's functions
In addition to dynamic drawings essential for animation
we will explore various compositions and framing techniques
that can enhance visual storytelling in video production
For the first lesson in Action Drawing
we will start with Action Animating
using the Walking Cycle
In this session
we will explore movement principles
using animation fundamentals
Additionally, we will learn how to animate
basic human movements such as walking, running, and lifting
by applying animation theories
Principles of Movement
In this session, we will examine
some fundamental principles from
action-focused animation genres
that can be applied to drawing
Among the 12 Principles of Animation, the first concept we will explore
is Arc
An arc refers to the curved path
that movements follow in animation
It's Arc
The illustration shows
how the pendulum swings around a fixed axis
In animation, all movement
is based on this principle
where an object has a pivot point and a center of
mass, creating smooth, curved motion
Natural movement tends to follow curves rather than straight lines
Even when looking at the arms and legs, they move like a pendulum
not in straight paths
but along curved trajectories
Let’s take a look
Imagine this as a shoulder, with the arm
and the hand at the end
The range of motion of the arm naturally forms an arc
If you rotate your arm in a full circle, you can see how it traces a curved path
This happens because most movements, whether humans or animals, are based on a pivot point or axis
Arc is essential because
like most elements in nature, especially living beings
our eyes perceive curved motion
as more natural and realistic
When movement follows an arc
viewers can more easily
predict and understand a character’s actions
Additionally, curves create more dynamic and engaging motion
preventing movements from looking rigid or unnatural
Let’s examine another example
This illustration shows what happens when movement appears linear
Focus on the image labeled "3" in the center
On the left, the motion follows a proper arc
and you can see that the lines
connecting points 1, 3, and 5 on the pendulum are even
However, on the right, notice how the line at position 3
is much shorter than on either side
In nature, movement rarely occurs in straight lines
It usually revolves around an axis or pivot point
This is a much easier way to see
the movements that draw an arc
Let’s look at a few more examples of arcs
As mentioned, arms and legs
move in arcs because they pivot from
the shoulders and hips
Also
if you consider the knee a pendulum
its motion will naturally follow an arc
Another example is elastic objects
like a rubber ball
What happens?
It rebounds in an arc
Like this
Throwing a ball to the ground
doesn’t bounce back in a straight line
it follows a curved trajectory
Similarly, throwing an object into the air travels
along a parabolic arc before landing
Now, let’s move on to the second key concept: Timing
Timing refers to the control of movement speed and rhythm
Looking at the example of a pendulum, notice how it starts moving slowly
speeds up in the middle
and then slows down again as it reaches the top
But how can we achieve this effect in animation?
At the start and end frames
the drawings are closely spaced together
frames 1, 2, 3 and, 5, 6, 7
are positioned near each other
while frame 4 in the middle is spaced farther apart
This principle is known as Slow In, Slow Out
Also called Ease In, Ease Out
It follows one of the fundamental animation rules
where motion starts slowly, accelerates in the middle, and slows down at the end
The more frames placed between movements
the slower the motion appears
Conversely, when fewer frames are used in a section
the motion appears faster
Timing is determined by the number of frames
placed between the start and end of a movement
For example, if an action is divided into 12 frames
the way those frames are distributed significantly
affects the movement’s nuance
Or, by adjusting the spacing like this
and omitting some frames
the nuance of the movement can make a huge difference
If all frames are evenly spaced
the motion will appear steady and slow
If the frames are compressed into 6 frames, the action will appear much faster
Timing is also used to depict external physical forces
like gravity and inertia
For instance
the acceleration caused by gravity
can be expressed through timing adjustments
Timing can also convey weight
not just speed changes
Generally, slower movements create a sense of heaviness
When expressing heaviness, the timing will be slow
but the slower the timing, the heavier it feels
regardless of the actual weight
Consider how your steps feel heavier
when you're exhausted
even though your body weight hasn’t changed
By adjusting movement nuances like this
timing can effectively express fatigue, a character’s emotional state
personality, or even the mood of a scene
Even in static drawings, like comics
choosing which moment of an action to depict
can be considered a use of timing
The third concept we will learn is Squash and Stretch
Among today's topics
this is the most crucial principle in drawing for animation
Squash and Stretch refers to
how an object’s shape deforms as it moves
Squash occurs when an object is compressed
For example, when a ball hits the ground
it flattens and widens
creating a squashed effect
Stretch happens when an object elongates
This often appears in dynamic motion
such as when a ball bounces back into the air
stretching vertically as it moves
Take a look at the bouncing ball example
The squash occurs when the ball
hits the ground and flattens increasing its horizontal width
The lowest point where the ball
is most compressed represents squash
Stretch happens just before and after impact
notice how the ball elongates vertically as it moves
Whether it’s stretching before hitting the ground or after bouncing upward
these deformations create a sense of motion
So, squash is mainly expressed in physical
or preparatory situations right before exercise
Stretch is now the part that stretches in the direction
of the exercise when force is applied
and the exercise is about to begin
These two expressions can be seen as the essence of cartoon drawing
Also, an important point in this concept is the change in the center of gravity
This concept where weight and flexibility
are expressed through shape transformation
is because the volume and center of gravity are maintained constant
even if the shape is exaggerated in this way
so the movement looks natural
So, in the case of this bouncing ball
when the squash occurs on the floor
hat is when it is pressed flat
it doesn't feel like it's pressed flat
but rather like the object has sunk
or shrunk, right?
Similarly, when it stretches
it feels like the object has stretched out for a while
but it doesn't feel like the volume has increased this much
So, the important thing is that the volume
shouldn't change much based on the visible area
For example, if it has doubled horizontally
it should be reduced vertically by twice as much
Also, the center of gravity is always located and maintained at the center of gravity
If it's shaking left and right
like when you bend your arms back
and stretch them forward
the body will be the axis, right?
The body is in the middle
so the center of gravity functions as an axis
If the center of gravity is deformed, it is out of orbit
so it must be protected
If it is deformed to this extent
we feel like we leaned back and then stretched forward
However, if the center of gravity is not here
but moved more to the side
t will also move to the side
Then, we feel that we have moved our body
so this body has stepped forward
This does not fit the concept of squash and stretch
So, the center of gravity must be protected
Also, squash and stretch are used
when the center of gravity moves, such as jumping or falling
For example
in this movement of lowering the body
the center of gravity moves downward as the body
is compressed through squash
When the center of gravity moves upward while jumping
stretch occurs
and the movement is naturally connected
In this way, the center of gravity
must move in the middle of the core
And you can also express weight
with squash and stretch
The heavier the object, the more the squash-pressing expression
appears and the more distinct the center of gravity is
You can feel this when you think of a light rubber ball
and a water balloon
Here is a rubber ball and a water balloon
Or, in the case of a ping-pong ball or a hard rubber ball
if it falls to the floor and collides like this
it is pressed slightly like this
and bounces back quickly like this
However, when a water balloon is pressed
it is pressed and squashed like this
And it will expand like this for both sides
The more the process of being pressed
the more frames there are
We learned this concept earlier
so the more frames there are
the slower and heavier it can feel
Also, since the area touching the floor
is much wider as it is pressed
the center of gravity feels closer to the floor
When you add a lot of these things, you can create
a lively expression that feels like a movement, even when drawing a still picture
Fundamental Movements of the Human Body
We will learn three simple movements
used in basic human body animation
Walking, running, and lifting
We will learn the three most basic movements
All three of these are affected by
gravity or other external forces
Gravity acts on everyone equally
so there are these immutable laws
Let's look at the stages of walking one by one
First is the contact stage
This is the beginning
The moment the front heel touches the front
the moment this part touches
the back foot pushes forward
This is the movement of pushing the body forward
The stage starts and progresses based on
the moment when a new step begins
and the area of ​​the front foot touches like this
Next, the body goes down a bit
The front knee bends, and the center of gravity moves slightly forward
The center of gravity that was here before
has now moved a little closer to the front foot
The back foot is completely pushed off
and almost off the ground
Now, the center of gravity is not working on the back foot
And the third is the passing pose
Now, the back foot is moving forward
and crossing the front foot, called the passing pose
The center of gravity is completely on the front foot behind first
Right?
Next is up
This is where the front foot pushes off the ground
and goes up slightly like this
This is the section where the body position is the highest
As you can see, the center of gravity is unstable
No foot is standing in the middle of this center of gravity
This back foot is behind
so it is a very momentary situation where it is supported only by the heel
Finally, contact again
The red opposite foot moving forward
has completely moved forward
When the back foot has completely moved forward
and the heel touches again
this is the end of the first contact
and the beginning of the other side
These five steps above are called the walking cycle
If you just follow these five steps
the key pose of the animation will be completely completed
Let's fix the center of gravity in these movements and connect them
The contact part and the down, the body goes down
Then, in the passing pose, you move forward
and in the full-up, you push the body completely forward
You finish by taking the last step on the opposite foot
Even though it's only five frames, the animation
that feels like walking has been completed
As such, these five movements are very important keys
Next, let's learn the running motion
Running motion is faster than walking
and requires dynamic drawing
The legs are stretched more
and the knees are raised much higher
The arms are not drawn here
but when we sprint
they are raised very high based on the hands or elbows
Since it is a dynamic posture
we can run in an attention posture
but making the motion bigger
suits the nuance of this running motion better
Also, a flight phase is added
where both feet are lifted off the ground at the same time
This up phase becomes the flight phas
This is quite different from walking
The body's center
is also tilted much further forward
than in the walking motion
If it were original, it would have been like this
Because
the width is wide before falling forward
you can quickly extend your feet to support yourself
The more the body leans forward
the more directional momentum is added
so the nuance of running can be emphasized more
Let's take a look at this
First, it starts with the same contact phase
It starts a little more dynamically
Since the center of gravity in jumping
is greater than the downward gravity
the vertical center of gravity is as important as the horizontal center of gravity
Right now, the center of gravity is low and unstable in the middle
Then, the next posture comes out just like that
The center of gravity is completely transferred to the feet
This can be considered the only stable posture
in the walking cycle of jumping
The legs absorb the shock when they hit the ground
and now they bend their knees slightly
to prepare for the forward propulsion
The leg coming out from behind like this
continues to come forward
Next is the passing pose
This intermediate phase is completely crossed
so the front foot is extended forward
And the back foot is completely pushing the ground
and launching
What is launching? It would be good for a stretch to occur, right?
At this time, it would be good to give the back leg a stretch like this
If you think of it as a stretchwhere it's just straight out
and a squash where a slightly bent contraction occurs
it's easy to apply
It's especially useful in dynamic movements
like this jumping motion
Next is the flight phase
Did you notice that a slightly different phase was added?
It's a posture where both feet come off the ground
and you're floating in the air like this
Since the center of gravity is now above
only the center of gravity above and below is meaningful
not left and right
If you look at the pendulum I showed you in the timing
you can see it as the 4th phase completely in the middle
So it's a part that passes by in an instant
The last contact phase begins again
When the heel of the forward leg touches the ground
it will be the next contact phase
If we draw a still picture of running
it would be good to express a passing pose or a posture
in the flight phase with enhanced dynamics and directionality
The last movement to learn is lifting
The most important thing to draw for lifting is the backbone
and the next thing to pay attention to is expressing weight
To express weight, focus on the squash when lowering the body
before lifting an object and the stretch when lifting
You can focus on this
The more the center of gravity is concentrated on the object, the more weight is felt
The more you bend your knees and extend your arms toward the object
the more the center of gravity moves from the person to the object
Then, shall we look at each movement?
First, there is an object like that and a person like that
Do you see the red line on the back?
That represents the line of the backbone
Please pay attention to how the backbone bends
and how it works when you apply force
You can focus on that
Now, shall we take a closer look?
First preparatory movement
You bend your body slightly to lift the object
Lower your body, bend your knees
and extend your arms towards the object
Your back straightens and arches inward
When the object is not bigv
and heavy, this movement is
often completed by holding it as is
and extending your arms to straighten your back
Like this
Second stage of preparation
While sticking the object to your body as much as possible
bend your back toward the object's outline
By sticking your body as tightly as possible to the object
you are expressing that the object is heavy
As the center of gravity sticks, it moves from your body to the object
Since the object is heavy
if the center of gravity is far from your body
it will be difficult to support yourself and stand
That is why you express that the center of gravity
is as close to the object as possible
Also, while sticking to your body
through this preparation movement
Back is bent, right?
Being bent means your body is stuck to the object
and contracted
which causes squash
That is why your body is compressed as much as possible
Also, since you will be stretching later
by applying force in the opposite direction
sticking as close as possible to the bottom
as
a preparation movement is better
Like this
Next is the lifting movement
As you lift the object while slightly straightening your legs
the center of gravity also goes up, right?
The top goes up, but the legs stay slightly apart
And the back, the back is not completely straightened
but slowly goes back, and the curve gradually becomes gentler
You can see that the force
is applied upwards, or in this case, to the upper right
as much as possible
Since you are applying a tremendous amount of force from here, the hand is heavy
so the weight is now going down due to gravity
and the shoulder is going up because it is trying to lift
Then what happens?
The arm will be pulled tight
Then, the arm part will also stretch
Here is the second lifting posture
When you try to lift it higher
you exert more force once more
and instead of holding it back and upwards like before
you exert a lot of force very suddenly
and your bent upper body will turn in the opposite direction
As you exert all your strength
your waist will bend in the opposite direction
Your chest will also expand like this, and you can’t see your stomach
but your upper body will move backward, and your arms will be pulled in more
It will stretch much more than before
In cartoonish terms, if you express your arms a little longer than before
and make them thinner, as if they are stretched like rubber bands
you will feel a better stretch
Stretching backward and upward is a movement
that is often expressed even when exerting all your strength
Next is the carrying phase
The first phase of carrying
Now, you have completely lifted the object to your chest
You can see that your chest is much more open than before
and unlike before, your stomach is much more protruded
and raised from the front line of your body
Because if you stick your stomach out, your back will also bend much more
which will cause a back injury
This should not happen
Also, since the center of gravity is higher in the picture
all the strength should be concentrated on the upper part
In the second carrying posture
you can see that your entire body is more firmly extended
and your spine is firmly extended
You can see that
This is not a squash or a stretch
but a stiff, straight line
When we lift heavy objects
if our backs are bent or curved like before, we get hurt
To fully support the weight and apply force
the bones of our back, or to be precise, the muscles that support the bones
must be tense and tensed
so that they are in a state like a rigid bar
A straight line is more suitable
than a curved line
Only after holding the muscles in this stable manner
can we carry it
Putting down posture
When you put down the object, your body
will surely go down
At the same time, the spine that was pulled tight or stretched out again
that is, the overall line of the body
if it was like this before
will bend inward and squash
The stretched line will squash again
As the tension in the body is completely released, the taut arms and body lines
can now be expressed as a curved line
Slightly bent
All the techniques expressed in lifting
as I explained several times earlier
can be applied not only to lifting heavy objects
but also to all movements that require strength
When you draw like this in the future
for example, when lifting a heavy object
don't draw it in a dry pose
with a hand at the end of the object
and it is just being held like this
If you draw it while using the nuances of the curve
and the sense of weight
you can express it vividly
Let's summarize what we learned in this lesson
First, we learned about the principles of
movement using the walking cycle
We also learned about the animation methods for
walking, running, and lifting
Thank you
Principles of movement Understanding movement using shapes
Arc: Movement in animation moves along an arc, and the audience can understand the character's actions more easily in the curved movement that draws an arc
Timing: Controlling the speed and rhythm of movement, determined by how many frames are inserted between the start and end of the movement
Squash & Stretch Squash: An expression of the shape widening as the ball flattens when it hits the ground Stretch: Refers to when an object stretches and becomes longer
Basic movements of the human body Walking Contact (start): The moment the front heel touches the ground, the back foot pushes forward Down: The body goes down slightly, and the back foot pushes off the ground and comes off
Passing pose (middle): The back foot moves forward and intersects the front foot Up: The front foot pushes off the ground and rises slightly Contact (end): When the back foot moves completely forward, it returns to step 1 (contact)
Running Contact: The front of the foot, not the heel, touches the ground Down: The center of gravity Transfer to the foot that touched the ground Passing pose: Extend the back leg and strongly press the ground
Up (flight): Both feet are lifted off the ground and are in the air Contact: The heel of the forward leg touches the ground and leads to the next step (contact)
Lifting Preparation 1: Lower the body to lift the object, bend the knees and extend the arms toward the object Preparation 2: Close the body to the object as much as possible and bend the back in the opposite direction
Lifting 1: Lift the object while straightening the legs and raising the center of gravity Lifting 2: When trying to lift a little higher, the bent back bends in the opposite direction as the force is applied backwards and upwards
Carrying: Chest rises more than the stomach to support the object Putting down: Lowering the object and squashing the body again as the body lowers