Original subtitles

- The time has come to give the final touch

to our bouncing ball animation.

To clearly understand what we need to modify,

I will change the frame rate of the animation

by going into the document option frame rate.

Here, we can find a bunch of preset

that will set the pace of our animation.

We are currently using the classic 24 frames per second,

but they generally use 30 frames per seconds.

Here, I will select a custom frame rate

and I will set it to five frames per second.

Now, when I play my animation,

it kind of play in slow motion.

It's a good way to identify the different position

of the bouncing ball,

and it can be a method to spot spacing troubles.

Switching back to 24 frames per second,

I will select the object

and go into the motion path panel.

I will set the animation range

from zero to 24 frames per second.

And since this is a function I use a lot,

I will right click on the calculate button

and add it to my quick favorite.

This way, when I press the cue key,

I can access the calculate function anywhere

in the 3D viewport.

You can now see our spacing

and try to see what's wrong with our animation.

When an object is falling in space,

it's accelerating until it touches the ground.

The speed of an object might stabilize

due to air friction.

But unless there is a force pulling our ball up,

it is simple to accelerate until it touches the ground.

So the spacing should be increasing

from one frame to the other while it's falling.

And we can see this is what's happening on those frames.

Each frames forward, the spacing is getting bigger.

On the last frame, the spacing is getting smaller.

It means that the ball is slowing down

before hitting the ground and this is incorrect.

And this is something that we can read on the curve.

As explained previously,

the curve should get more and more vertical

as it get closer to the value zero,

which is our ground value.

While here we can see that it has this S shape

that makes the ball slowing down before touching the ground.

The curve is easing out toward the ground.

But since we have made a good blocking of our animation,

it doesn't look that bad.

Those two breakdowns are currently helping us

getting a better result.

This is why blocking can be pretty important.

To fix the ground key frames,

we just need to switch the handle pressing V to vector.

Now I no longer have this S shape on my curve.

To make things even clearer,

let's get rid of our two break down key frames

by selecting them and pressing the X key.

I've also switched back to basic ball handles.

When I play the animation,

you will better feel this ease in and ease out.

You can see the ball accelerating

when it's leaving the ground and before it hits the ground.

While if I switch both handles to vector,

now we can feel that the ball is bouncing.

To get even a better feeling,

I will also slightly raise the curve

by moving both vector handles towards the outside.

And by scaling the upper key,

I will make the ball raising faster

and holding a bit more in the air.

I have bring more contrast into my animation

by changing the shape of the curve,

and now it's more stylized.

A little touch we can add

to make it even more appealing,

is to slightly offset the upper key of one frame.

This way we don't have the same timing

when the ball is rising than when it's falling down.

We can recalculate the motion path of our animation

by clicking the update path button.

And instead of the in range option,

I've switched to around frame.

From there I can choose how many frame

I want to see on my motion path

before and after the current position of the ball.

Now, when I look at the spacing of my ball,

we can see that when it's leaving the ground,

it has the biggest spacing.

And it's slowing down when reaching the highest position,

which is correct.

When the ball is falling down,

we also get the proper spacing.

It's getting bigger and bigger

as we approach the contacting key frame.

We now have a pretty cool bouncing rhythm,

so let's work a bit on the scaling of our ball

or more precisely on it's squashing and stretching.

Pressing Alt+H in the graph editor

will reveal all the curve.

I can hide the Z location curve,

so that we focus on the scale curve.

Since our balls squashing is pretty brutal,

we can switch those key frames to vector.

If we have a very slow squashing,

we will have kept them as it is,

as the ball would be progressively absorbing

the impact for its squash.

Pardon for the animation,

I'm trying to get a feeling of the motion of the ball.

When the ball squash,

we can imagine it's a continuity of its fall.

And since we are working on the cycling animation,

the latest frame is the same as the first.

So if I check the frame before the latest,

I can see that I have a big spacing

between the base of my ball and the ground.

So it will be better if I kept this thinner

for the spacing of the squashing.

Meaning that I will offset the squash pose

of frame two on frame one.

And we will have a very stretched pose on frame zero

and a very squashed one on frame one.

And so it will transition with the full better.

We are now getting a more impactful squashing

if we compare with previous version.

But since we have offset one frame for the squashing,

we should do the same for the stretching.

As you can see my spacing

between frame three and four is very small.

So I want a faster animation.

I will offset the keys one frame before,

and I will also switch them to vector.

Next is the air squashing.

I offset the key frame where the ball recover

its round shape and then it's getting squashed again

with the inner star when it's reached the highest point.

Since the highest point is on frame 15,

I will make it squash on frame 15.

I'd like to slightly delay the squashing,

so what I will do is that I will duplicate all the keys

on frame eight and offset them onto frame 10 or 11.

It makes all the skate curve becoming flat,

which means that from frame eight to frame 11,

the ball is perfectly round.

And as the ball will be accelerating

to get back to the ground.

I'd like to slightly offset the time

it's starts to stretch by two frames

because the ball is falling faster than it is raising.

So making it stretching a little sooner does make sense.

Animating is not a linear art,

you will need to go back and forth a lot of time.

And while the animation gets more appealing,

I feel like there is something a little off

and since we've been offsetting a lot of curve,

the ball is starting to relax

while it hasn't left the ground.

Meaning that the ball should be in air on frame four.

So I just need to re-edit the curve for the Z location

and offset the stopping point by one frame.

And now when they play again my animation,

I feel like there is something a bit off

on the air squashing.

The ball slows and then it starts squashing.

And if we double check the spacing of the base of the ball,

we can see that as soon as it starts squashing,

the easing gets stronger and that's better.

The yellow arrows are getting smaller progressively,

while there is a big difference between the two red arrows.

So even if it's very subtle,

it makes the animation a bit weird.

So again I can fix this

by simply offsetting the squashing key frames,

the plateau we have created before just by one frame.

Making it happening a little sooner,

so that it will better blend while it's raising.

I guess you may ask yourself how do I get rid

of the grid of the motion path,

et cetera my fried issue.

It's by deactivating the overlay here.

And since this is something I do all the time,

what I did is that I set a shortcut onto the overlay.

You can assign the shortcut to any tool

or option in blender by simply

right clicking on it and selecting assign shortcuts.

I've personally used the shortcut power two

which is just upon the tab key on my French keyboard.

I'm pretty happy with this bouncing ball animation.

And in summary we have seen that curve editing

can dramatically change our animation.

Good blocking makes your animation a little better

when you switch to spline.

It's important not to be afraid to break the curve

using vector handles.

Offsetting the key by one frame

can really change your animation and make it look better

on its troy.

Don't forget that the devil is in the details.