Working with the fundamental skeleton is ideal for animating a character's main body, but what about other areas such as the eyes, Grae's wings, Kila's hair, and even her chest? To make the character appear more realistic, these areas should animate, too.
Kila and Grae's eyes need the ability to move, so first we will create joints to animate them. Follow these steps for both characters, as their eyes will work the same.
That's the eyes in position. We will look into adding more joints in the way of facial animation in Chapter 13.
As Kila moves around, it would be nice to add a little bounce to her bosom, giving her a bit more life and making her seem more organic. We can approach this enhancement in two ways: using either joints rotations or translations to add animation.
If we use the translations method, we have freedom to move the joints anywhere in space. Also, the main pivot point will actually be inside each breast, meaning we are essentially picking each breast up and moving it around. Using rotations limits the movement to around the pivot point itself. This is ideal for rotational-based animation, on which the majority of the body is based. What you need to find out at this stage is how the joints are handled when they are exported and placed into the game. If the engine can only handle rotations, then the decision is made for you.
But which method is best? It depends on the area you are animating and what you need it to do; in this instance, both techniques will provide good results. Let's take a look.
Open up the file named KilaChestTest.mb.
Press Play in the Time Slider, and you'll notice that the movement of both breasts is almost identical, yet the one on the right is controlled via translations whereas the left side is controlled by the joints' rotations. The only initial difference can be seen when you look from the side. As the chest rises, the breast controlled via rotations tilts upward as it rotates.
Look at the joint configuration for the two techniques in Figure 11.19. As you can see, the joints on the left, which control the breast via rotations, have to be quite far back, just past the spine in fact. Having the joints too close to the breast will cause it to tilt upward unnaturally as it rises and falls.
Figure 11.19. Two different chest joint configurations
With the joints placed actually inside the breast, as shown in the torso on the right of Figure 11.19, controlling them with their translations will initially give you a good idea of how they will moveas well as giving you more freedom over where they move.
Using translations to manipulate your geometry will allow you to animate it through all three degrees of movement. With rotations, on the other hand, you are locked to the pivot point and so can only move the breast up and down and twist it. Using translations, however, lets you move it up, down, and in and out.
So for Kila, we opt for the translation methodbut in other projects, make sure you check on which methods are possible for your game environment, and think first about what you want the area to do.
Kila's hair is quite long, so if it doesn't have some movement it won't look natural. Ideally, the hair would be controlled by an in-game physics engine, but for the purposes of this book we will add some joints to give it basic movement.
We could create lots of joints, giving us the freedom to do anything we want with the hair, but its current topology and associated joint restrictions mean we have to rely on fewer joints.
We now have the ability to add some movement to her hair.
Grae's wings, like Kila's hair, need the ability to move. You should already have a wing setup left over from Chapter 6. We can use that here, saving us the effort of creating a new one.
First we need to address the wings' ability to open and close. With the current joint hierarchy we can't do this (Figure 11.21, left). The single joint at the wrist rotates all the fingers of the wing; we need to be able to rotate these individually.
Figure 11.21. Adjust the wing hierarchy so that the wing can open and close.
As you can see in Figure 11.21, right, we can now open and close the wing by using the new joints we've created.
Now that the wing is easier to pose, we can go about attaching it to the main skeleton and mirroring it for the wing on the right.