Rigging the Eyes

Let’s start with the eyes. You’ll use a Track To constraint to control where Jim’s eyes are looking. In Figure 11.3, you can see what the eye rig looks like. Again, you’re only working on the left side of the rig for now.

Figure 11.3 The eye’s rig

The following list describes the steps for creating the eye’s rig. You need to create the bone that will move the eye’s model and it can be a little tricky in this case because you have an eye that is being deformed by the Lattice modifier. In normal models, the eye would be a perfect sphere, so you’d have only a single bone with its head in the center of the eye, but in this case, you’ll use two different bones.

1. First, select the eye’s mesh and, in Edit Mode, select the central loop and press Shift + S to move the 3D cursor to the loop’s center. Exit Edit Mode and you’ll see how the 3D cursor is not actually centered in the eye at all; don’t worry, because the eye will be rotated from the 3D cursor’s position before the Lattice modifier deformation takes place. Now, go to Edit Mode in the armature and create a bone at the 3D cursor’s location. Duplicate the bone and move the new bone to the approximate point from which the deformed eye would rotate. You’ll use this bone later to deform the eyelids slightly when you rotate the eye to create a more organic effect. That’s why the first bone is a helper and is only there to rotate the eye, while the second bone is a deformer because it will deform the eyelids. Parent these two bones to the C_D_head bone, so when you move the head, they will follow it.

2. Duplicate one of those bones and move it forward to be in front of the head. You need to end up with two new bones, one that is in the center of the two eyes, in front of the head that will control where the eyes look, and a second one that will be in front of the left eye. C_eye_target will be parented to C_look_target, so when you move the latter, the former will follow it. This will give you the ability to make Jim’s eyes look in whatever direction you want, but at the same time, you’ll have independent control over each eye.

3. Now add the constraints. First, select C_eye_target and with Shift pressed, select H_eye. Press Ctrl + Shift + C and select the Track To constraint. The bone first selected will automatically become the target of that constraint you just applied to H_eye. Now, if you move C_look_target, C_eye_target should follow and H_eye should reorient itself to look at its target. Repeat this process with D_eye.