- Alright, so let's talk about key frames.
My play head was on frame 1 when I drew this shape,
so I got a key frame on frame 1.
See the blue down here?
And if we look up here,
this is where the key frames are logged, right here.
I have one key frame out of one.
The bright blue says I am on that key frame.
So let's have a little fun with this.
I'm going to shrink this down
and maybe put it in the corner.
We'll jump out here to frame 50,
put it up here,
stretch it up, maybe give it a rotate,
and then we'll jump to frame 100,
put it down here and squeeze it.
Let's set our timeline to bounce,
and go back to the beginning.
Deselect and play.
There we go, a lovely animation.
Using the control points and the transform rectangle, okay?
Now up here, I can track my control points.
This is jump back to the previous key frames.
I'm on key frame 1 out of 3.
Jump forward to the next key frame, 2 out of 3.
Jump forward to the next key frame, 3 out of 3.
To delete a key frame,
go to the key frame in question
and hit the key minus button.
Key frame gone.
Now I've only got two key frames.
I can jump to the first one and jump to the last one.
However, if I want to insert a key frame,
of course, anytime I pick it up and move it,
I'm going to add a key frame,
so if I just grab this guy and do that,
boom, I've got a new key frame, and we undo that.
What I wanted to show you is
if you've got a play head
somewhere in your non key frame area,
you can click on key plus,
and that frame will become a key frame.
Okay, let's delete this guy.
With him selected,
I'll just click on the minus key and he goes away.
Now I'm going to show you
the important functional difference
between animating shape
using its control points versus the transform tab.
Back to the roto tab.
I'm going to draw
a rectangle here.
Okay.
Oops, I wanted my play head to be on frame 1.
Whatever am I going to do?
Well, I can just say,
delete this key frame here.
See?
Zero, zero.
Jump the play head to frame 1 and then say,
give me a new key frame,
then I just fixed my boo-boo.
Alright, so I've got a little rectangle.
Key frame on frame 1.
Go to the last key frame.
I'm going to select all the control points,
and I'm going to rotate it 180 degrees.
Seems simple enough.
Okay.
Deselect, jump back to frame 1.
Now let's draw a second rectangle just like this one.
Okay,
and he's got a key frame on frame 1.
Now you'll notice I have rectangle 2 selected, okay?
Rectangle 1 on the left, rectangle 2 on the right.
Go to the transform tab now.
Here I have transforms
for the entire shape.
This is the point.
The transform tab moves it as a single, solid polygon.
So I'm on frame 1 down here,
and I'll jump to the last frame and I will rotate this guy.
Let's see, we'll go this way, 180 degrees.
Alright, now let's watch the difference in behavior.
Deselect and play.
You see?
Very different results, and the reason is
that with the control point animation,
each control point is moving in a straight line,
from its start position to its destination position.
Whereas over here,
I'm using a transform on the entire shape,
so it's moving as a solid object.
So these control points
are in fact moving in arcs or circles.
Okay?
Whereas, the individual control points
move in straight lines only.
Remember that when you're key framing things.
The interpolation for the control points
is going to be just a straight line.
The interpolation for a transform
of the entire shape will incorporate curves.
Okay, let's deselect and jump back to frame 1.
Now let's talk about naming shapes.
Double click on the shape and it lights up,
and I can name this guy left.
Double click on this guy.
Whoa, I should of called him right,
so I just showed you how to edit the name.
Okay, we'll make this one left.
Okay, so this is the right shape, and the left shape.
Now you can group shapes together
by adding a folder and putting them inside the folder.
We select root and that's what the plus sign is for,
is add a folder.
Click on that,
and I'm going to call this group,
'cause that's what it's really doing.
Now I can select these two shapes.
Hold down the shift key so I get 'em both.
Drag them and drop them inside that folder.
If I fold it up, it can go away,
so you can do a lot of tidy up.
Let's unfold that.
Now I can apply a transformation to the folder,
and you see, it lights up the transform tab.
Now I can move them as a group
and key frame the entire folder.
Okay, let's put these back to default,
and let's take a look at the shape tab.
The shape tab allows you to adjust
a few attributes of each individual shape.
I'll select the right shape.
To do this, we want to see this in RGB.
So I'm going to switch the viewer to RGB,
and we're going to go to the roto tab
and tell it to draw the shape in the RGB channels now, okay?
Alright, so back to the shape tab.
The reason I did that
is because I want to show you some color.
I can't do color if it's always in the alpha channel.
I'll select the right shape.
We'll go to this guy here and say,
be blue, thank you very much.
The other thing you can do with the shape tab
is invert the shape,
which means it will flood fill
outside the shape instead of inside.
Right shape which is blue is selected if I invert.
I flood fill outside with blue everywhere.
Let's put that back.
Okay, now it's time to look at some motion blur.
So let's go back to the roto tab
and let's get rid of all this stuff here.
I'll select a group and minus.
Poof, everybody's gone.
Let's go get another rectangle.
Make sure my play head is on frame 1.
I'm going to draw a nice rectangle here.
Now remember, we set the output to be RGB.
So let me switch it back to the alpha channel,
and then we'll switch the viewer to the alpha channel.
This is where you're normally drawing your rotos.
Okay, time for some motion blur,
but first, I need some motion,
so I'm going to go to the transform tab
and first thing I'm going to do is repull my pivot point,
same method as everywhere.
Alt commander control,
click and drag to repull the pivot point.
I am on frame 1, so I can drag this guy over.
By the way, when you're doing a rotate
using the onscreen control jack,
if you want real precise control,
simply slide way out here,
and now you've got really fine control
over the rotation, okay?
Very nice.
Alright, I'm going to jump out just 24 frames
and rotate this guy over here.
Alright, we've got the bounce mode
turned on for the play head.
I'm going to set it outpoint
so the play head stays constrained and we will play,
and there we go.
So I've got myself a little action for motion blur.
Okay, we'll stop that.
With the shape in question selected,
we go to the motion blur tab.
Now the shape mode turns on motion blur
for each individual shape.
The problem is when you've got a lot of rotos,
which you will have,
the overlapping shapes can run into rendering problems.
So what you want to do there is the global attribute,
the global motion blur.
Okay?
So we push in here,
and you can see I've got some motion blur.
Okay?
Alright, if you want to increase
the amount of motion blur,
as with all motion blur tabs,
you increase the shutter.
If you increase it enough,
you're going to start to see banding,
and that's when you increase the motion blur number.
Remember, motion blur number is really a quality number,
not a size number,
so we put those back to default and rehold the viewer.
So mastering the roto node
is a critical skill for any new compositor,
so in the next video,
we'll see how to use it
to see how to rotoscope part of a character walk cycle.