Precompositions and Echo Effects in Animation

So that loops, but there's only one of them. Okay, so there are keyframes in the cell one layer. There is an expression of the cell one layer, but there is still only one cell one layer.

I would like to be able to reuse this. So we created nested compositions, precomps, previously. When we needed to string multiple scenes together, we use precomps for that, okay? Again, precomps and the comps, same difference.

But a more, a very common use of it is here. We have a layer we've built animation for, and we wanna be able to have multiple copies of that same layer, all based on the original. Okay, so it means if we change the original, they all update.

Smart objects in Photoshop, symbols in Illustrator. It's based on the concept, okay? So I'm gonna precomp this layer. Right-click, precompose.

The keyboard, I never use that. The keyboard shortcut is Command-Shift-C or Control-Shift-C, okay? You can call it Bob for all it cares, but there's a choice. Be careful with double-clicking.

You just go to the window, yeah, right-click, yeah. So right-click, precompose, or Command-Shift-C, Control-Shift-C is the keyboard shortcut. If you have a single layer selected, it actually gives you a choice.

Now, by the way, if you have multiple layers selected when you do this, because you're combining multiple layers together, there's no choice. But leave all attributes in circulation. Move all attributes into the new composition, okay? Okay, now here's the problem.

Now, I know what the commands do, but reading the description doesn't help. So leave all attributes in circulation. Use this option to create a new intermediate composition with only cell one in it.

The new composition will become the source to the current layer. Move all attributes. Use this option to place the current set of layers together into a new intermediate composition, okay? So first of all, this is a child.

So basically, this is gonna take the layer, either way you do this, it's gonna take the layer and turn the layer into a comp. Now, the problem with this is it doesn't tell you what attributes are. Attributes are everything that the layer has.

So if you added an effect, that's an attribute. If you have changed the layer's position, rotation, scale, that's an attribute. If you've turned on some of the switches over here, that's an attribute, okay? So what do you wanna happen to all the properties of it? So the position animation that I built is an attribute.

Leave all attributes would take the layer source, which is that video file, put it into the new comp, but then paste the keyframes position onto the new layer, which means it would not be reusable because the animation would not be in the comp. It would be on the layer again. I need that.

Move all attributes creates literally a reusable animation. Okay? Sometimes, it doesn't matter which of those two you choose, but most of the time, it sure does, okay? Sure does, move all attributes. Again, if you have multiple layers selected, it can't give you a choice.

It has to push everything into the new comp, okay? So like that, then okay. And if I play it, nothing has changed. Still the same content, okay? But if you tap U, nothing happens because there are no keyframes here.

I wanna rename the layer, okay, but now. Okay, so what happened to the keyframes? They are physically in the new comp, okay? There is literally a new comp in your project panel, okay? That's the source. If anybody here uses InDesign, this concept is kind of like the idea of parent pages, master pages, if I totally, but only kind of.

So if I go into the blood cell comp, which I misspelled, by the way, and I change something in there, like I just changed the direction or I add an effect to that, like change the color or something. Maybe I make them like orange here. Oh, I know, it'll be blue blood, blue blood.

Wait, how do I make blue blood? Tritone would do it, tritone would do it. A blue blood cell changed in the original parent comp. Back to circulation, it is now a blue blood cell.

If I use, duplicate that layer and do it again, it'll be a blue blood cell. That's that, okay? So whatever you do to change the content of that comp layer affects every use of it, which is nice. Okay, so that's duplicating.

Now, by the way, the instructions have you do an effect to make multiple copies of that at once. The effect is called echo, E-C-H-O. So one of the reasons that I precomp this is because one, I wanna be able to have a main object I can adjust, but two, echo wouldn't work if I applied it directly to the layer source.

I have to apply it to a comp. Echo, basically what it does is shows me time-delayed copies of that content. That's the original, that is a copy of it one hundredth of a second back, sorry, three hundredth of a second back in time, okay? That's five copies of it, this is 10 copies of it.

Each of them is that amount of time back before the other. So it's like showing earlier frames is what it's doing. Why are they brightening like this? Because echo has this blending mode setting.

Composite in back, puts the original one in back, each one, new one is in front of it. Composite in front, opposite behavior of that. Why? Because they use this to do like motion trail effects.

Because there's a little decay option here on here, 0.5. They kind of fade out, you get a motion trail behavior. Okay, now by the way, it doesn't want you to do that in the instructions, so I'm gonna reset that. Echo operate, I believe this is maximum in the instructions, but it's not touching each other, it's irrelevant pretty much.

But it has you change the echo time. I'm gonna hold down Command and just lower that number a bit, so they spread out. And if I do this right, I can pretty much have them kind of on screen consistently, that's what it does.