All language subtitles for 02-07-Animation-curves

- Animation curves is one
of the beginners' nightmare.

But I want them to
become your best friends.

To display the animation
curve of our ball,

let's go into the graph editor.

Right now, our curve looks a bit boxy,

not really curved, and this is because

we are still in constant interpolation.

But it will help us reading them.

The curve are just a
graphical representation

of the value over time.

The yellow controller point accurately

the different key frame
we have inserted before.

If I select the yellow
point on the blue curve

at frame 7, it has a value of 4.

such as the Z location of our ball.

And if I now display all
the object transform channel

in the graph editor,

we can see that the Z
location is highlighted.

So the control point I've
selected in the graph editor

is the key frame value of
the Z location of our ball.

If I double click on
one of these channels,

it will select all the control
point of the current curve.

You can hide and unhide curve

as you would do with any
object in the 3D view.

If I press Shift + H,
I will hide everything

but the selected curve.

Or you can click on the little eye icon

to choose whether you want
to see or not the curve.

With G, I can move the curve.

I can press G+Y to constrained
the movement on the Y axis

or G+X to constrained on the X axis.

Before we start reading those curve,

let's get rid of any of
the curve we don't need.

Since our ball is not rotating,

we can get rid of all
the Euler rotation curve

by pressing X.

And we can also get rid
of the X and Y locations

since our ball is just moving up and down.

This is a good practice to get
rid of any unwanted channel

to keep your graph editor clean.

We can find the Z corresponding value

onto the control point of the curve,

but also in the transform
channel of the object.

Pressing the N key will
open the F-curve panel.

This is a little (inexact) here
to check the position value

and interpolation mode
of the key frame channel.

Let's now select all
the key frames, press T,

and switch to Bayesian interpolation.

If we now play the animation,

we get way smoother motion of the ball.

When you switch from step
mode to Bayesian mode

or curve mode, we call
this the splining stage.

If we have a quick look to our curve now,

we can see that the Z location curve

is getting higher value when
the ball is getting higher.

I will unhide the scale channel
by clicking the eye icon.

I will select the first
controller point of those curve

and press the dot key on
the Num pad to zoom on it.

You can easily identify
the Z scale channel,

which is in blue, allow
us to control the height

of the ball.

And the X and Y that are
one on top of the other

that allow us to control
the width of the ball.

Let's check a couple of
example to betterly understand

the behavior of the curves.

In this example,

the curve is controlling
the rotation of the arrow

from a value of -90 degree to +90 degree.

The curve is rising rapidly

before easing into the frame number 24.

And when we scrub through the animation,

we can see that we have big
spacing in the beginning

of the animation, and it
gets lower in the end.

You seeing the motion
we will have a preview

on the spacing of this animation.

And now, we can obviously
see the difference of spacing

during the animation.

And the more vertical the curve
is, the larger the spacing.

The more horizontal it gets,
the smaller the spacing is.

In other word, the more
vertical the curve,

the faster the animation.

The more horizontal, the slower.

In the next example, let's
consider the X location curve

of the ball being the time.

It goes forward in a linear fashion

Now, if I activate the Z location curve,

and I frame it properly, look
at all the Z location curve

and the motion path we on
in the 3D view port align

or are comparable.

Again, when the curve is vertical,

the sphere will rise rapidly.

And as the curve gets more horizontal,

the sphere rise slower.

So if I now give an S shape to my curve,

the ball will move
slowly in the beginning,

then in the middle of the animation,

it will accelerate as the
curve get more vertical,

and in the end, it will slow down.

We are creating an easing
out from the frame zero

into an easing in the frame 24.

And since we still have the linear motion

of the sphere on its X axis,

we can see that the Z
curve really looks like

the motion path of the sphere.

Since my sphere is
moving on the X location

in a linear fashion, any
modification I will add

to the Z curve will show in the 3D view

as in the graph editor by
updating the motion path.

You can use the few example
available in the file

to play with the curve and
recalculate the motion path

and check out the spacing.

Back to the rotation example,

I've modeled the curve so that

I have a fast acceleration
in the beginning,

then a plateau, and then
an ease out and ease in.

And it absolutely reflect
on the motion path.

The pretty vertical shape of the curve

on the first two frame
generate a big spacing.

The plateau shape or
flat shape of the curve

indicate that the value
is not changing over time,

so the arrow will stop,

while the final S shape of the curve

show an acceleration then a deceleration

into the final frame.

To summarize, we have
seen that a curve is just

a representation of the
evolution of a value over time.

The more vertical the curve shape,

the faster the value change.

And it translates in bigger spacing.

The more horizontal the
curve, the slower the change.

Motion wise, it translate
in smaller spacing.

A flat curve indicates that there is

absolutely no change in the value

and so no motion.