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- Importing Illustrator or Photoshop files into After Effects
- Animating shapes
- Organizing scenes with null layers
- Working with the Puppet tool
- Creating replacement animation using time remapping
- Automating head turns
- Creating a master control node with Expression Controls effects
- Setting up a scene for animation
- Animating dialogue
Skill Level Intermediate
Replacement animation is one of the more common ways to animate, and the way you do it is you basically take one image, and you swap it out for another. This is particularly useful for things like mouth, blinks, and in this case we're going to use it for hands. So let me show you some of the basic techniques of creating a simple and efficient method for doing replacement animation in After Effects. So we're going to first start with the left hand, and if you notice here I've got five hands, and all I need to do is Shift+Select those, and you can see we have them here in the Timeline here, Hand 1 through Hand 5.
So with all of my hands selected, I just go Layer > Precompose. Once I do that, it gives me a menu here. It says, "what's the name of your new composition?" And in this case I am going to go LEFT HAND, and I like typing everything in caps so that way I know it's another composition, and then just click OK. It gives me a composition called LEFT HAND, and puts that into my main Timeline. If I double-click on this, you'll see that all of those layers are now in this subcomposition, so I have Hand 1 through Hand 5.
Now, in order to animate the replacement, I do need to get these kind of aligned. So I am just going to select all of these and move them over the initial hand here, and then I am going to zoom in a little bit. And I want to do a real close fine-tuning. The easiest way to do that is just to turn off layers and select each one, one at a time, and make sure that everything is pretty much lined up, because what we are going to be doing is swapping from one to the other, so we don't want any jumps.
So I want to get this as close as I can. Now, once I have them all aligned, I can now trim my composition to match. Now, the reason I trim my composition is, if I zoom all the way out you'll realize that I've got all of this blank space around here, and my hands are really just kind of occupying this small area. And more importantly is, when I go over to my main composition, you'll see that, because I have this kind of big layer, it consumes the entire workspace here in my actual composition.
So if I am trying to select something, a lot of times I inadvertently select the hands, because it has that big of an area. So I kind of want to just tighten it up a bit. So if I go over to LEFT HAND -- and let me just go ahead and zoom in just a little bit here -- I can go ahead and trim my composition using what's called region of interest. So all I need to do is select this button here, and then just draw a little box around my hands. And I can go ahead and adjust that box; in fact, I can zoom in here and get it really tight if I want to.
I just want to make sure that every bit of those hands are within that box, so I am going to give it a little bit of space on the top and bottom, and so on. So now, once I have that region of interest set, I can do Composition > Crop Comp to Region of Interest, and all that does is it shrinks down my composition so that it matches the size of my hands. And now when I go over into my main composition, you can see now I've just got a little bit of selection here, so it's not taking up the whole screen.
Now that we have everything arranged, let's go ahead and set up the actual animation that we are going to use to create replacement animation. So what I need to do is animate these hands one hand per frame, so just turn them on and off one frame at a time. I need to shrink down my Timeline so that it is only 5 frames long; I need to make my composition 5 frames. So let's go into Composition Settings. I have five hands, so I need 5 frames. So instead of 900 frames, I am going to do 5 frames.
So now that I have that, all I need to do now is sequence them one hand per frame. So the easiest way to do that is to select them all, and then just grab the edge of them on the Timeline, and shrink each one down to one frame. So now I have them basically all on one frame, and then I can just sequence the layers. So all I have to do is right- click over this, Keyframe Assistant > Sequence layers, click OK. This is my first frame, second frame, third, fourth, fifth; so five frames, five hands.
Now when I go into my main composition here -- let's go ahead and zoom in here so we can see this. I am going to zoom in on the Timeline as well. You'll see that I have got an animation where I have one per frame, but that's not really what I want, is I actually want to be able to control which hand turns on at any given frame. So I can do that by using a feature called time remapping. So all I do is select the layer, right-click over it, under Time > Enable Time Remapping.
When you click on that, things change, and you get this little entry here that says Time Remap with a number and two keyframes. So if I slide over here, you notice that it's still animating between hands, but this number is increasing. And basically what it's telling us is that this number is telling which frame to display. So if I can delete these keyframes, at least delete this first keyframe, you can now use this number and just slide through and animate the hand. So if I wanted to have this hand on Frame 1, or Frame 0, this hand on Frame 3, I can do that.
Now, the one problem with this is that it will continue in-between these. So when you animate these using time remapping, you do have to change the interpolation from Linear to Hold. So when you animate using Hold, notice how the shape of the keyframes change, and now it will hold this until it gets to the next frame. So all you have to do is animate with Hold, and you can just switch whatever one you want. So if I want to go over here and dial in a different hand, I can do that.
So those are some of the basics for animating replacement objects. Now, I did this just for hands, but you can do it for a lot of other types of objects. You can do it for blinks, mouths; a lot of people use it for feet and shoes as well. Practice this on the other hand and get some familiarity with this process, because it's very important.
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