All language subtitles for 08-12-01-Polishing the bag

- [Instructor] Regarding the
bag, more than polishing stage,

it's going to be an animation stage.

While the blocking did help to get an idea

of what we were going to do

and what would be the behavior

of the bag during the animation,

since the main controller animation

or motion is pretty simple,

it's almost easier to work
directly in the graph editor

for this kind of motion.

And then we will rework
the different tweaker bones

or even erase all the key
frames and rebuild their motion.

Since the bag has a pendulum motion

with an extreme low and an extreme high,

it's useless to have more
than three key frames.

One for the beginning,
one for the extreme,

and one for the return.

So at this stage, I'm getting rid

of any useless key frames I
did during the blocking stage.

From there, I can start
working on the X rotation axis,

which is the main rotation axis
of our bag in the beginning.

In the beginning, it's pretty close

to what we were doing with the character.

I have two contact frames with the fist.

After the first punch, the
bag starts to move a bit.

Then, during the second punch,

I'm keeping the bag a
bit backward to make sure

that the fist penetrates the bag.

Don't over-focus on this part though

because this is something
I'm going to change later on.

But this gives me the starting point

for the first pendulum motion of the bag.

And once you have that, you
just need your starting point

and where the bag will
end before the next punch.

And we just need one key in between,

so I will get rid of
everything but those two keys.

Then, we just need to
convert the start and end key

to vector, and then work on the scaling

of the handles of the extreme key

exactly as we will do with
the up and down motion

of a bouncing ball.

From there, you need to watch
several times your motion.

See if it feels right, and
then edit any of your keys.

Maybe scale a bit up or
down some of the handles

to accelerate or decelerate the bag

whenever it's going down or up.

Here, you can see the final
shape of my X rotation curve

on the first bounce.

Regarding the X and Y rotation curve,

during the first swing, there
is not that too much to do

than getting rid of any keys
that could be in between.

And set the handles of the
starting and ending keys

to vector so that we
have no interpolation.

I haven't done it on the Y rotation.

That's a mistake, but
it's not even noticeable

in the animation.

On there, I need to redefine the moment

where the bag will start to move.

It's currently one frame earlier
that what I have right now,

and since I want to hold the pose

for the first impact of the hook,

I will simply duplicate the
keys from 45 onto frame 47.

This will create a plateau

where the bag is no longer moving,

and I can get rid of
the keys after this one.

Here, we've just defined
the starting point

of the pendulum motion of
the bag after the hook.

Now, I will go on the next
contact frame on frame 78,

and I will refine the position of the bag

so that it perfectly matches
the shin of the character.

I've now defined the starting point

and the end point of this
next pendulum motion.

So, I can get rid of all
the key frames in between

and rework its motion.

From there, I will rebuild some kind

of the same curve we had
with the bouncing ball

or the previous pendulum motion.

I will select the Z
rotation rotation curve

that is going to be the
main rotation channel

for this specific bounce.

I will duplicate the key.

I put it right in the middle
and switch it to auto clamp.

Then, I will make sure that the starting

and ending keys are set to vector.

From there, I have my base
motion for the second bounce.

From there, I definitely
need some more love.

I will refine the position
of the hitting frame.

From there, I will bring
a little more contrast

into the shape of the Z curve

as you can see on the reference.

This way, the bag will be pushed faster

and will come back faster,
which will look more impactful.

And from there, I've worked
a bit on the X rotation curve

so that the motion of
the bag was currently

physically correct because
in its current state,

the bag has a weird motion from frame 60,

where it starts to rotate to the left

while there is absolutely no force

that would generate this rotation.

So just after the punch,

I will put a bit of a right rotation,

and then the bag will
swing back to the left.

Polishing the motion of the bag

just after the kick was a bit closer

to what we did during the
polishing of the character.

As I'm making the bag holding a bit

onto the character's shin,

and then it starts to swing very fast.

Once the bag is projected
after frame 80 'til frame 85

where it gets out of the camera range,

its motion is pretty close
to what we already had

with initial keys set to vector

and then a big acceleration.

From there, since I want the
bag to land flat on the ground,

I just got rid of all the keys
on the X and Y rotation axis.

Then, start working on the root controller

of the punching bag.

And again, here it is gonna
be super simple compared

to what we have done before.

So, the first thing is that I can get rid

of all the key frames before
the root starts to move.

Then, I will get rid of any key frames

between the starting and landing pose.

Then, I will have refine
the location of the bag

once it hits the ground
based on the camera frame.

And from there, I will
convert all the keys

to vector because why?

Well, one, there won't be
any change in the speed

of the bag on your recent channel.

So on the X and Y location channels

exactly as for the bouncing ball.

A few frames after the hit,

I will slightly offset the
value of the Y location curve

so that it feels like
the bag is sliding a bit

on the ground.

I've done the same with
the X location curve,

and I will convert both
keys to auto clamped.

Then, I just need to scale those two keys

to create a heavy feeling
as the friction of the bag

on the ground slowing down.

Now, the only curve that needs

to be worked on is the Z location curve,

and as you can see, it's
going to be super simple.

Now, the only thing I'd like to improve is

as for the character, the
silhouette of the bag.

As it currently lands on the ground,

we just see the top part of the bag.

And if we were only
keeping this still frame,

we wouldn't be able to
identify a punching bag.

So, basically this is a bad pose.

First thing I will do is use
the master rotation controller

to make sure that the bag
is flat on the ground.

From there, we get back
onto the root controller

of the bag, and I will
use its Z rotation axis

to rotate it a bit to the side.

Since the bag is airborne,
its rotation will be linear.

And then just after the impact,

I've pushed a little bit
the rotation further,

and I've made it ease.

This is to simulate the friction
of the bag on the ground

and the fact that it's slowing down.

The bag is rapidly
stabilizing on the ground,

and I haven't added any bounce
so that it feels very heavy.