Original subtitles

So when we're working with the curves, we're dealing with the animation,

and they're might be a piece of animation in the

curve that we really want to repeat.

Repeating part of the curve is easy.

In this example, if I hit the Play button,

the earth does a little shimmy move back and forth at about frame 50.

So let's say we like that shimmy and we want to loop the animation

that we saw between frames 50 and frames 83.

I'm going to go down here and really quick I'm going to look at the

different values that each of these keyframes has,

so that I know that they line up.

If I double-click here,

I'm going to just change this to 450 so it's a nice round number,

I'm going to go to this keyframe,

I'm going to change this by double- clicking on this to 450

to make sure it's the same round number,

and then I'm going to right-click and I'm going to

come down to Predefined and Loop.

And if I set the first frame to frame 50,

and the last frame of the loop to frame 83,

you'll see we get a nice looping animation,

and now throughout our entire timeline,

we get that same shimmy throughout the entire thing.

So that's how you loop something,

but now let's take a look at how you reverse a curve.

I'm going to Ctrl+Z to undo,

and then I'm going to move this Curve Editor over here,

and I'm just using my middle-mouse button to pan over

and using my scroll bar to pan back,

and let's say I wanted to reverse this curve.

I could just go here, pick reverse, and it's going to duplicate my curve,

but it's going to duplicate my curve in a negative range.

So it's going to duplicate the same curve over here into negative space,

and I can just go over here, and I can drag these keys,

and I can slide this over, it's a little counter-intuitive,

until my curve is back in the positive space.

I'll hit Ctrl+Z to undo that,

and I wanted to show you that I just did that the wrong way.

What you want to do is you want to marquee select all of these key points and

you want to hover over the crosshairs until you get this icon,

this little back and forth icon,

and that'll make sure that your frames stay locked,

and that you're only moving things along the X axis,

and you get this back to 0.

and that way you make sure that these up and down values don't change at

all to get this reversed animation back to frame 0.

So now if we play this, we've got the reversed shimmy,

and that's what we're looking for.

Now if we want to do a true reverse of the curve,

that's called a negate,

which is basically going to mirror or flop all of our keyframes.

So if I Ctrl+Z to get us back to the normal animation that we had,

and I right-click in the Curve Editor,

I see this predefined button and I select Negate,

and Negate is going to give us the mirror opposite

of the curves that we had before.

So if I play this through, we get a flipped form of the animation we had before.

In the next clip, we'll take a look at using expressions to modify a curve.

This just means we're going to take expressions or mathematical equations

and pipe them into the Expression Editor to give us noise,

or random values,

or certain interval curves that give us a form of procedural

animation that you'll probably be using quite a bit.