Original subtitles

- [Instructor] Let's polish our bouncing ball.

The first thing I will do

is select all the key, press T

and switch to Bezier.

Now we have interpolation between our keyframes

and the first thing we can see

that we get some slowing down

or easing before the ball touch the ground.

You can switch to the graph editor

through the header or pressing Control + tab

when you are in the action editor.

I have activated the display selected only

and I will start polishing the route of my ball.

When looking at the curve,

I can see that only the z and y curves

are currently animated.

All the rotation, scaling and x location curve are flat.

To make my editing easier,

I will expand the root panel

and I will just hide all the curves

that I'm not using,

only keeping the z and y location curve.

Remember what we have seen in the previous chapter.

When an object is falling,

it is at its maximum speed

just before hitting the ground,

so I can select my z contacting keyframe,

press V and switch it to three

and then rotate the left handle

to get a proper curve.

It already feels way better.

But I'm a bit disturbed by the y motion of the ball.

The frame just before it contact the ground

looks a bit weird.

And this is because we have easing on our y curve.

The y curve has an S shape

between the IS point

and it's contacting pull.

But as seen in the previous chapter,

when a ball is falling,

it is accelerating until it touch the ground

but its motion forward is pretty constant

because even if there is air friction

that will slow down the ball,

on such a motion, it's barely noticeable.

So I can switch both handles to free our vector

and align them to get a more linear interpolation.

So as a first polishing path or splining path,

I will simply repeat this process on each bounce.

To get a clean viewport,

I'm activating and deactivating the overlay

with a shortcut I've set previously.

So I will break all the z-axis handle

by switching them to vector

on the contacting frame.

I will remove the intermediate frame on the y-axis

because it's useless

since we will create a linear interpolation

between the contacting and air pose,

switching our handles to vector.

I will use this method each time the ball is airborne

but on the final stage of the animation,

I will keep the easing toward the very last keyframe.

So as you remember in the previous chapter,

I like to keep the ball a bit longer in the air generally

just for style sake.

So on the z curve,

I will take each key where the ball is in the air

and I will slightly scale the handles.

This way, the ball will rise a little faster in the air

and it will be kind of thwarting a bit.

Please consider that animation is not a linear workflow.

And I will remove some keyframe,

remove them, retime some part of the animation

and tweak it a lot.

So it's a lot of back and forth

before you achieve a decent result.

And you can tweak an animation forever

but there is a moment where you have to stop.

Before the second bounce,

I feel like there is a slight glitch in the animation

because the ball is staying too long on the ground.

So I will shorten this hold on the ground by one key,

offsetting all the keys after key number 20.

As it does improve the animation,

I will do the same between frame 25 and 26.

There is a hold on the ground

but I feel it's too much.

So I will get rid of frame 26

by offsetting it onto frame 25

so that on the very last bounce,

the ball is staying on the ground only for one frame

instead of two.

If we now have a closer look to our y curve,

we can see that we have a pretty logical pattern.

Each time the ball touch the ground,

the y curve get flatter and flatter,

meaning that the ball is losing speed

on each impact but when airborne,

it has a linear movement.

And as soon as it stays on the ground,

we will have a slight easing

from frame 29 to frame 43

when the ball is slowing down.

Watching the animation again and again,

I feel like there are still some glitches

and some bugs I have to fix

and when having a closer look at my z curve,

I can see that I have some easing

after the impact, which is not correct.

So I will fix this.

After those modification,

my animation should look better

but I still have some glitches.

And this is because all the transformation we have done

with the squash and stretch

haven't been polished

and haven't be retimed.

I've made a few modification

on the timing of the route of my ball,

so now the other animation that were in sync

during the blocking stage

are no longer in sync.

So I will deactivate all the other transform channel

just to see my root motion.

And now I can see that it feels way better.

So there is still this moment

where the ball stops on the ground

but this is because we will have motion

through the squash and stretch.

So without the squash and stretch,

it looks a bit weird

but as I renabled it and as I will be polishing it,

I will be able to fix the problem here.

If you want your animation to look a bit more realistic,

just remove those holding frame

and just make the contacting pose on one frame.

Then reduce a bit the squash and stretch.

This is just a matter of personal preferences.

I like it a bit stylized,

so I'll keep those holding poses.

I will now work on the upper squash and stretch controller.

This one is going to be pretty easy to polish.

I select the first keyframe

and press on the dot key on the num pad to frame them.

I'm mainly watching the orientation of the ball created

by the stretching effect.

You can also calculate the motion path of this ball

if this does help.

Here what I want is to give back a bit of verticality

to the ball.

So I will slightly offset the beginning

of the stretching on the y-axis.

I will hide the z curve by clicking the I icon

and then select the first keyframe,

press Shift + D to duplicate it

and move the duplicated key on frame three.

As it looks a bit too delayed,

I will move back this key on frame number two

and then I will switch the handle type to three

so that I can shape a bit the curve.

This way, I have a better feeling

that the ball is currently aiming

or pointing toward its landing spot.

Then I will work on the z curve

that currently squash and stretch the ball the most.

And I will just switch the impact point to vector

because this is an impact frame

where the ball switch from squashing to stretching again.

Then I will go onto the next jump.

I will reselect my root bone

and I will recalculate the motion path

because it does help me figuring

where the ball is supposed to land

and also where the top of the ball

is supposed to be pointing at

and this is why here,

I will slightly push the top to the ball forward

toward the previous keyframe position

by pushing my z curve a bit up in the graph editor.

I scrub a bit onto my animation

to see how it does move.

Then I will select the z-axis curve,

switch it to vector on this middle frame

and then move forward toward the next jump.

First, I feel like it's offset in time.

So I will select all the curves

and move them by one keyframe prior to the current one.

The ball is currently leaning too much backward

on on these three

and I can figure this by watching the F curve value.

When selecting the keyframe,

I can see that its value is set to -65

and if I select the previous one, it has -56.

It means that this last keyframe is further away

from its value zero

so it means the controller is offset more

and so it's more deforming the ball

than the previous bounce,

which doesn't make sense since this bounce

is less powerful,

losing energy compared to the previous bounce.

So I will push this keyframe

towards zero in the graph editor.

For the very last bounce of the ball,

I don't want any deformation.

So I will just get rid of the next keyframes.

From there, we can watch our animation several time

and jump into polishing the next squashing controller.

I will select the lower green controller

and since the curve are pretty small,

I will use the normalize option

to be able to see my green channel.

Since we have used the upper green controller

to give an orientation to the bounces of the ball,

I don't need to do the same

with the lower controller.

So I will just make my y curve flat

by removing the keys that are offset

because they won't bring anything good to our animation

and they are currently almost useless

as their value is very small.

So just get rid of them.

Now regarding the z-axis

that will allow us to squash the ball in the air

when it's reaching its highest point,

I want it to be very subtle.

So I will offset the starting and ending keyframe

of those motion by two frames.

And I will repeat this process along the whole animation.

I will shorten the length of this motion

and as I go forward,

I will reduce the amplitude of the curve

because again, with energy loss,

I will get the less squash and stretch on this motion.

This controller allow us to add very subtle deformation

to the ball, so it's interesting

to make it as good as possible.

When I'm done with it,

we can clearly see the energy loss

during the motion of the ball.

I will fix the timing of the last squash

because it doesn't occur at the right time.

It's supposed to happen

when the ball is at its highest point.

And then again I can watch my animation several time

to see if it looks okay.

So that's great.

We have a bouncing ball but it's not rolling.

This is because we haven't animated the rotation controller

of the ball yet.

In this case, it wouldn't make sense

to block the spinning of the ball.

Since it doesn't change its shape,

we wouldn't be able to see any change

during the blocking stage.

So I will select all the keyframes

but the first one and get rid of them.

Just press X and confirm.

Then select the first keyframe

and move it on frame eight.

This is the frame where the ball

is contacting the ground.

So I get a flat curve

from frame zero to frame eight.

It means that the ball won't be rolling

while it's in the air.

I want it to start spinning

when it will touch the ground

and when part of the energy of the impact

will be transferred to its rotation.

I will duplicate again the keyframe

and move it to move frame 18.

This is where I want the ball to be spinning already.

Nothing happens because I have disabled

the transform channel.

I need to reenable it.

Now when I move the curve,

the ball should be rotating

but it's barely noticeable

and this is because I need

to unzoom in my graph editor.

Since the value of the rotation is in degree,

I need to drastically modify the curve

and move it onto way higher or lower values

in this case.

Pushing the value down to -360 degree

will make the roll spin forward.

So that's fine.

On the impact, the ball will get full rotation speed,

so I will switch this to vector.

Due to the frequency of the rotation

and the animation, I have a hard time figuring out

if the ball is currently rotating or not

because the ball pattern seems to get aligned

on each frame so it's a bit weird.

So I will get rid of the overlay

to have a better vision of it.

I will also switch the second handle

to vector two because the rotation of the ball

is not supposed to slow in the air

and since I still have some difficulties

to read the rotation,

I will enable all the other controller keyframe

and disable their influence on the animation

so that I can clearly see

if my ball is rotating or not.

The initial air rotation speed

of our bouncing ball is not that important.

What will be important

is the final rotation speed

because it will have to match the speed

of the ball traveling on the ground.

So what we need to do is to duplicate the current keyframe

and move it on the next contact post.

And we need to make the ball spinning a little less faster

than the previous pose

because it's losing energy on each bounce,

so it's also losing rotation speed.

Then we will create a last keyframe on frame 43.

It's the frame where the bouncing ball

is currently stopping in space.

And this time we will switch it's handle type

to Bezier because we need some easing in the end.

We don't need a linear interpolation.

The ball is slowing down

so its rotation is also slowing down.

To make this stage readable, I need the grid

because I will need a point of reference in space

to see if the pattern of the ball

is still aligned with it whenever it's rolling

on the ground.

So I will re-enable the overlay

and I will zoom a lot onto my animation.

Now I will try to find the point

of reference using the pattern of the ball

and the grid.

When I find it, I will Shift and right click on it

to place the 3D cursor.

Now what I want is to make sure

that the pattern of the ball

is pointing toward the 3D cursor as the ball stop.

To do so, just zoom a lot

and then fine tweak the position of your last keyframe.

You will also need to slightly tweak the rotation

or orientation and scale of the last handle

to make sure that we don't have this sliding effect

on the ground.

Just do it by little touch.

If you see that your animation is completely off,

it means that your whole curve is completely off

and the difference between your final key

and the previous key, the key from frame 30

is way too big.

Rotation easing when you have a contact pose

is pretty hard to get right on the first shot,

so be patient, tweak your curve

until you get this nice rotation on the ground

and the feeling that the ball is really rolling onto it.

And if you can't achieve this, don't panic.

Open a new Blender file

and just make the ball rolling and stopping.

Work on the curve until you get this animation right

and you will understand the relationship

between your rotation curve and your translation curve.

It's not a question of math or geometry or whatever.

It's just a question of practice.

It might be a bit complicated at first

but with a bit of training,

you will get comfortable

with this kind of motion pretty soon.

And if you really want to get good at animation,

it's very important

because you will use animation curves every day.

So from there, I can call this animation done

but there were a few glitches

that I wanted to fix.

Those are little things,

so I won't be going in details into it.

I've just added a very small additional bounce at the end

and I've a bit revised the z amplitude of my route

so that the ball get a more even bouncing.

So there is not much you will learn

from the next step.

I'm just refining some of the poses.

I'm doing what we've been doing just before,

slightly revising the timing,

the amplitude of the curve, et cetera.

What you need to understand

is that again, an animation

is never finished until you say stop.

And just work your animation

until you get to a point of satisfaction.

If you're struggling with the animation,

start a new one.

And this is the only way you will progress.

I've said this before

and I will say it a lot of time during this course,

you need to animate to become a good animator.

You need to make this bouncing ball exercise multiple time

until you will get a good result.

This is how it works.

I am still struggling

to get a good bouncing ball result

after several years of animation.

And to bring a character to life,

to animate a character,

you need to first be able

to give it motion and then you will input personality,

input emotion but before you input emotion,

even into a bouncing ball,

you need to learn motion.

All right, enough of philosophical discussion.

Let's go ahead with the next video.