All language subtitles for 03-12-03-Polishing the run Cycle - Legs

- [Instructor] In this video,

we are going to polish
the legs of the character.

It's pretty important

because it will help
defining the silhouette

of our character.

It will also communicate
its weight and agility.

Here you can see the final result

of the whole character polished.

Try to use the file
provided as a reference.

Since they are the biggest,

I will start with the back
legs of the character.

Since we are using inverse
kinematic mechanism

for those leg, the location

are the most influential transform channel

for the animation of the legs.

This is the first channel
we are going to edit.

Now the legs of our character

are dragging a lot toward the ground,

making them looks very heavy,

and like our character has
a hard time raising them.

So we will need to rework the leg position

while in the air.

But we do need to keep a bit of delay

on the leg motion

since they are dragged by the body.

And the first thing I will do

is to offset by one frame
all the keys on frame six,

putting a bit of delay
on the air extreme pose

of the leg.

From the side view, I will
be working on the z location

and y location curve of the leg.

So I will hide all the other channel

and focus on those curves.

And while I'm polishing
the motion of the foot,

I'm watching every single frame.

The further you get
from the center of mass

of your character, the
biggest will be the arcs.

So when you are animating legs or hands

on a character,

it's very important to
track what you are doing

and to polish it as much as possible

'cause a sudden gap in your curve

will make the motion of
those parts very broad

or very large.

You will get a big glitch into the arc.

Another thing to remember
is that a falling object

will accelerate before it hits the ground.

So make sure that your spacing

is the biggest before hitting the ground

and when leaving the ground.

And you can convert the contacting frame

with the ground to vector.

It's the best way to avoid
easing in the first step.

Finally, to have a better readability

of the first leg,

what I will do is go in front view

and press Alt + B

and frame off of the character.

It will enable the view clipping mode.

It's like creating a tunnel

and whatever is outside of this tunnel

won't be shown in the 3D viewport.

It's support handy to cut the visibility

of your character in half.

While it's very useful
in modeling for sure,

that's also very useful in animation.

Just press Alt + B again

to clear the clipping view.

I'll advise you to
calculate the motion path

of the foot as soon as possible.

You can see that I have a
very decent arc right away

but I will polish it
using the motion path.

The main thing I will focus on here

is to make sure that the
character is pulling his leg

as high as possible when jumping.

So it will drag in the beginning

and then it will catch up
and even get very close

to its belly.

So as my arcs looks very smooth

and as I'm pretty satisfied
with the motion of the leg,

I will switch to the front view

to work on the x location
curve of the leg.

Here the method is pretty simple.

You want to avoid zigzagging motion.

And when the foot is stuck on the ground,

you may not have any
left and right motion.

So polishing the x curve

is pretty straightforward.

We apply the same rule
as when we are working

on the under curve.

Whenever the leg is contacting the ground,

I will switch the handle type to vector.

The next channel that
inputs the most motion

into the foot then will be the x rotation.

So this is the next curve
I will be working on.

While I was pretty satisfied on the arc

of the leg here,

I've made quite a big mistake.

I've worked the foot animation only

without root motion and that's a mistake.

I advise you to check your animation with

and without root motion
as often as possible

because in the end, what
you will be animating

or seeing into your animation

will be your character
moving with the root motion.

It will be moving forward,

not moving on place like that.

And while the arc of the leg looks cool

without root motion,

when I've enabled the root motion,

it didn't look that great.

It's not going to be a major
issue on the animation here

but I will have to fix it later on.

So that's an issue.

And you will save time if
you switch to root motion

as soon as possible.

Back to our foot x rotation.

The main focus is to
get a smooth transition

while in the air

and to get a pretty fast flopping motion

when leaving the ground.

The foot is pushing the body forward.

This is why we have a pretty big change

between frame two and frame four

and I'm polishing the
curve between frame one

and frame two so that
the foot doesn't clip

with the ground,

which is represented by the y-axis here.

One of my main concern

was to choose whether I
would input foot roll or not.

And I've decided to go ahead with it.

That's why our character is
landing on the ball of the foot

and then it switches to
a flat foot position.

You can think of it as a foot roll

from the heel to the toes

but on digit grad, like
cat, dogs or squirrel,

the heel is currently
not touching the ground.

So I'm not here to give
you an anatomic course

but it's important to take
this into consideration

because you will intuitively
translate human motion

onto animal motion.

While it can work or be a stylized choice,

it's important again to watch reference

of animal and understand the behavior

of the different part of their body,

depending on their function or purpose.

Here I'm polishing the x
and y rotation of the foot.

The idea is to make the
foot point a little inward

when it's leaving the ground

and point a little outward

when it's going to contact the ground.

One last thing, on the contact frame,

I want the foot to contact
with the ground slightly

with its outer edge.

This is a very subtle motion you will find

in the foot motion of a human being

during a walk cycle.

The foot has a slight
tilt from left to right,

while pushing on the ground.

So even if it's very subtle,

it's better to input this information

in the foot motion of
our squirrel character.

When I got onto polishing
the other back leg,

finally made the clearer move

to check my animation
with the root motion on

as I told you in the
beginning of this video.

And this is where I
spotted the weird curvature

of my arc for the left leg.

You can see some kind of vertical easing

on the motion path.

We had to get back onto the
polishing of the left leg.

Fix this issue.

And that's perfectly normal

that you have to refine
every single controller

each time you are polishing one of them.

As I told before, since
everything is connected,

fixing a bug somewhere
or a bad motion somewhere

may modify the perception
you have of the other part

and you will have to polish it again.

As every art form, an
animation is never finished.

It's up to you and your schedule

to call it done.

The second important point

is to watch the silhouette
of your character.

I don't think there is a
shortcut in Blender to do so

but you can go to the shading option,

switch to flat and then object.

This way, your character will
turn into a single solid color

that will help reading its silhouette.

The idea is to avoid some part of the body

to overlap and make the
silhouette harder to understand.

For example, here if I overlay both feet,

one one top of each other,

the silhouette is harder to understand.

While if I separate them,

I can see there are two feet.

So this is not something you will be able

to manage all the time

because sometimes, the point of view

makes your body part overlapping

but just keep it in mind.

That's also why the position of the heel

is slightly offset so that
we can see both heels tip.

On the final polishing stage,

I have tweaked the
position of the pull target

to make sure that the legs

were not pointing outward too much.

This is not really about
polishing any motion here.

It's mostly about fixing bugs
from the inverse kinematic.

But I'm moving the controller in space

whenever I feel the need,

then playing with its curve.

So I will lead you there
with a little time lapse

where I will be polishing both back legs

and I'll see you a little
later in this video

to polish the front legs.

(tranquil music)

For the front leg, I didn't
make the same mistake

as for the back leg

and mainly worked with root motion.

The process is basically the
same as for the back leg,

so I will just give you the two key points

that you have to figure
out for this motion.

The front legs are the
first to get in contact

with the ground when your
character is landing.

While it's important to make them drag

in the beginning of the jump,

when the character is
then losing altitude,

it's important to show that
the squirrel is in control.

So you may not swing the
arms all the way around.

Since we want to show that our character

is in control of its run cycle,

then he will aim at the
target point he will land on

with his arms.

If we look at this reference

where the character is shaking his arms

and legs all the way around,

we clearly understand
that he's not in control

of the situation.

Again, you have ask yourself
how to move the legs

but also why you will move
them in a certain way.

Again, animation is
like any other art form.

If you want to make it believable,

it has to make sense.

From the timing, the
behavior of our character

is mainly based on its weight,

its agility, et cetera

but as we go along in this course,

we will try to ask also ourself

how does my character feel?

And how can we translate those emotion

through motion, through animation?

So keep this in mind whenever
you are animating something.

The other thing here I want to avoid

is to have the legs or
front arm over extending.

This current rig is stretchable

but it doesn't look that
good on this character.

And also, even if the
animation is a bit stylized,

I'd like to keep it on the
realistic side of things.

I advise you to try to keep
this animation grounded,

at least for this chapter

because later on,

when we will be working
on humanoid character,

we will push the style a little further.

Realistic animation is
a very hard exercise

because it's about very subtle motion.

Here I have a couple of frame

where the character has
his front foot contacting

with the ground.

I've placed the 3D cursor as a guide

by Shift + right clicking

and tweaking the y location curve,

I will make sure that the
foot is on the same position

on both contacting frame.

Then I will duplicate the
last frame on the first one

so that both the first and
last frame of the cycle

are the same as usual.

So here you have the key component
to polish the front legs.

Avoid overextending limb,

avoid unnecessary and
goofy motion of the limbs,

aim at the landing point.

Make sure that the feet stays in place

whenever there are
contacting with the ground

and don't forget to check the silhouette

whenever you are working
on both front legs.

I will leave you there
with a little time lapse

of me finishing this polish

and I'll see you in the next video

where we are going to polish
the tail of our character.

(tranquil music)