Join George Maestri for an in-depth discussion in this video Designing joints, part of Creating Animated Characters in After Effects.
As you start layering your characters, you want to make sure that your joints have the proper overlap so that they animate well. Now, this is most important in the elbows, and the knees, but also the shoulders and hips can be important as well. But let's take a look at this character's elbows, and let's make sure that we have the right overlap so that this animates well. So I'm going to go ahead and zoom in a little bit here to his arm so that we can see it.
Right now, it's all in one piece, but we want to cut out this forearm so that we can bend it at the elbow. Now imagine what an elbow does: it rotates, so a rotation is basically a movement around a circle. So we want these joints to overlap with a circular outline. So the easiest way to do this is to select our Elliptical Marquee tool, and if want, we can do a fixed ratio of 1:1, and that will force it to be a circle. So then what we can do is just draw a circle that's the width of the arm, and make sure that we position it right where we want the elbow to be.
Now once we do that, we have the overlap; we have the outline, so all we need to do is just select the rest of the arm and go from there. So I'm just going to select my Polygonal Lasso tool, or Lasso tool, hold down the Shift key, and I just want to make sure I intersect right there at the tangent, and then just select the rest of my arm, and there we go. Now once I have this, all I have to do now is just do a Cut and a Paste, and now I've got this arm in the right place.
Now notice how I've got kind of a divot here, but we can fix that later. So all I want to do is make sure that this fits, basically, into that little divot. And the reason we have a circular outline is because when we start to animate this, you want to make sure that that is rotating around that circular outline, and if we have that right, you'll see how it makes a much better animation. So once I have this, I can now basically fill in the difference there.
So I'm just going to zoom in a little bit more so I can see, and again, just create a circular outline here. I use my Elliptical Marquee; make sure that fits. Let's do this, draw this one more time. There we go. And I'm just going to use my arrow keys to kind of fill in there. And once I have that, then all I have to do is make sure I'm on the proper layer, select my Paintbrush, and then -- or my Fill tool -- and I can just fill that in. Okay.
So now that I have both of these, I can move this into place here, and I should have pretty good joint action. So now let's go ahead and just hit Transform, move my pivot point to the center of that elbow, and now when I rotate you'll see how I have a pretty good animation. So we can do this for all joints in the character, and again, this is very similar to what we did with the head and the neck.
You want some pixels behind what you are animating so that we don't get any holes in the character. Now, this works the same for Illustrator. All you have to do is make sure that your shapes have a circular overlap as well.
- 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