In this tutorial we're going to look at Playback in After Effects for previewing. I'm going to hit 'space bar'. And you might find that with all the stuff we've done so far it's done the Playback pretty slowly. You can see, it's trying to keep up, and trying to redraw but it just can't keep up anymore. So, the easy things to do is, in the previous tutorial I changed to this, I have a habit of doing it. Don't do this. This changes the output of the actual Comp when you export. In some instances, most of the time it doesn't. So, we were set to 'Auto'. And what we're going to do is open up the Preview window. 'Window', 'Preview', if you can't find it… and what we want to do is change the resolution of the preview. Not the exported Comp. Down to 'Quarter', and what you'll find is… I hit 'space bar'. And it does a really good job of really kind of, like not of Resolution, so it's not pretty. So you might find our Resolution that works for Half, or Third, or Quarter, but it plays back nice and fast. Yes, it's working good. So that's the big one to get you going.

The other thing you can do is you'll Disk Cache. So under 'After Effects', 'Preferences' 'Media and Disk Cache', on a Mac. If you're on PC, it's under 'Edit' and it's down the bottom here, under 'Preferences'. I'm looking for the same one called 'Media and Disk Cache'. And in here, what ends up happening is, when you're previewing, what happens is After Effects stores that Preview somewhere, and it stores it in the Disk Cache. My Settings here are set to 93GB. So I'm telling After Effects, take 93GB of my hard drive to store all of your Previews. Now, if you're working on a computer that has very limited storage, what you'll find is, After Effects is filling up your hard drive with this kind of temporary files. And what you can do is 'Empty Disk Cache'. Mine's only got 2.2GB in here because I cleaned it up about five minutes ago. I'm going to click 'OK', and go to the one that says 'Clean Database & Cache' as well.

Now hopefully you'll notice a difference in playback. Especially if your hard drive is nearly full. It will clear off loads of room. And what you might say is, actually, you kind of have 93GB and what have you got left? If you've got 10MB left on your hard drive, get it to 5. The only problem is the Preview's are not going to be very long. It's going to have to redraw every time you hit space bar. So what causes the really bad playback? You noticed, at the beginning of this course it was running super smooth. But what's happened now is, probably the biggest thing for us is, we've added a camera, and we've made all these objects 3D. There's a lot of calculations that have to go into it now.

The other thing is Motion Blur. I've added to all the Layers that takes lots of memory to get going. If you've enabled any of this Vector redrawing, that can take a lot of memory if you're using live action video. We're just using static stuff here. It all takes a toll on the poor old machine. Another easy one is to close down any other programs. We've been using Illustrator quite a bit through this course. So close that down, and just open it up when you need to. So go through and close down anything non-essential.

The other things you can do is, over here, in our Preview panel, this one here, probably the next best one here is, 'Skip'. At the moment, it's trying to render every frame for you. So I'm going to stick it up to not 'Quarter' maybe, but 'Half'. So it's going to render, watch. It's not quite keeping up, it's a bit too slow. So what we can say is, skip every second frame, please. And what it's going to do is, it's going to be a little bit jumpier. But it's going to do it's best to kind of render every second one. So it's going to be a little bit jumpy, tiny bit. I find it's hard to notice. Let's skip out '5' so we can exaggerate this a bit. I may be able to go to 5, but what I want to show you-- can you see, it's keeping up a lot better. It's actually keeping up fine now. So it's just rendering every fifth frame instead of every frame. It's not going to affect the output. So I'm going to turn mine back to '0'. It's going to look fine. The problem is, if you change it here, every time you come back in here, it's going to be this crappy resolution, and you might be like, "Oh, what's wrong?" And you start playing around with the Vector Redraw, and it's actually just turned the resolution down here to 'Half'. So remember what you've done.

Okay, two more items to cover. One is, what you can do if you got a laptop, and it's just not running very well is, if you just want to upgrade your machine often, the easiest, and cheapest, and best thing you can do is RAM. If you got a machine, and it's got 4GB of RAM, After Effects is pretty much not going to work. But check, often laptops can be upgraded, especially PCs. And you can install more RAM. It's really cheap, it's easy to do. Lots of centers will do it, I've done it myself. And I'm not much of a computer nerd when it comes to hardware. You can check how much you've got by going up to 'Preferences'. Remember, on a PC, it's under 'Edit', 'Preferences'. Then go into 'Media & Disk Cache'. Actually no, you want to go the other way. It's under 'Memory'.

In here, I have 16GB of RAM on my MacBook Pro, and I'm allowing After Effects to use 11 of it. If yours, say it's got installed RAM of 8, you are at the bare minimum. If you've got 4, life's going to be tough for doing animation. And if you've got a bigger computer, and got 32 or 64, or any sort of chunky number, I envy you. 16 is the biggest I could get in this Macbook Pro that I just bought. Let's click 'OK'.

The last thing we're going to look at is doing our little Preview. Say, we're going to preview it. This is more of just general previewing. I'm going to turn it down from 'Half' down to 'Quarter' so it actually previews. So when it starts playing-- actually I'm just playing with that Transition there. I want to go back, play it. Go back, play it. So instead of doing it, what you can do is this little bar along the top, it's called the Work Area. The beginning of it, and the end of it. You can't see them, we're going to zoom all the way up by hitting the colon key on your keyboard. It's next to L. Tap it once, you go all the way in, tap it again, and it comes all the way out. It's zoomed all the way out. So I can see the beginning and the end.

What I'm going to do is, I'm going to say-- say I want to look at this Transition here. I'm going to bring this to there. And as long as my Play Head starts anywhere inside of here, watch what happens when I hit space bar, I got nothing on the keyboard now. This loops in there. So that's really handy, instead of having to go back to the beginning loop it all the way through, or be dragging the Play Head back and forth. This little Work Area can be useful. It can be a bit of a pain now as well. If you want to get rid of it, just double click in the middle, Work Area expands out, and we're back to normal.

All right, that is how to try and speed poor old After Effects up if it's struggling.