Game Character Development with Maya

2017-07-07 02:10:07

Now that the main rig for both characters is complete, we can set up the other areas that need to have life. These are the eyes, Kila's chest and hair, and Grae's wings.

Eyes

Both characters' eyes need the ability to move as they look around. The best way to achieve this is to create an icon that the eyes always look at, much the way the head follows the head icon. For the eyes, however, we can't use IK because we only have a single joint.

Import the file called Icon_Eyes.mb into your scene. You will now have two separate eye-shaped icons.

Point-snap each eye icon to its corresponding joint. Scale them and then rotate them so they are the correct orientation, as seen in Figure 12.69, top. Then move them out (using Z only) in front of the head until they line up with the head icon (Figure 12.69, bottom). Freeze the transforms.

Figure 12.69. Snap the eye icons to the eye joints, and move them out to the head icon.

Aligning the Eye Icons

As you can see in Figure 12.70, left, the eyes and the head do not line up correctly. This isn't a major problem and it's not important to fix. But if you want to, here's how:

Figure 12.70. You might want to adjust the head icon's edit points to match the scale of the eyes.

Right-click the head icon and select Edit Points (Figure 12.70, middle). Select all the edit points, and move and scale them so they line up with the eyes (Figure 12.70, right). We edit the icon in Component mode, because we won't need to freeze the transforms or make further adjustments to the hierarchy.

With the eyes in position, we can wire them up to control the joints. Select the left eye icon and then the left eye joint. Apply an aim constraint with Aim Vector set to 1 in the Z channel (0 in X and Y), and with Up Vector set to 1 in the Y channel (0 in X and Z).

Apply the same aim constraint to the right eye icon and the right eye joint, using the same settings as for the left eye.

The eyes are separate at present, but want to move them together. Select both eye icons and group them, calling the group EyeControl.

For all new groups, the pivot is placed at the world root, so go to Modify > Center Pivot and place the pivot between the eyes.

Make the group's selection handle visible so you can select it easily. Do this by going to Display > Component Display > Selection Handle.

To finish up, make the eye icons always face the eyes, as we did with the head icon. Select the main head joint and then the EyeControl group, and perform another aim constraint. This time set Aim Vector to 1 in the Z channel. Also, enable Maintain Offset if the eye group is higher than the head joint.

The eyes are now rigged, but as you move the icon around, you won't see much of a difference to the joints. To see the eyes moving, select the joints and go to Display > Component Display > Local Rotation Axis. Now you will see that the axes always follow the EyeControl icon because they were told to always aim at them.

Kila's Chest

It's quite easy to rig Kila's bosom; we merely need to point-constrain each joint to an icon that will drive it.

1.	Start by creating two more NURBS circles, calling them LeftBreast and RightBreast.
2.	Position each circle as shown in Figure 12.71, left, so each circle is in front of a breast. Freeze the transforms. Figure 12.71. Add control icons to the breasts.
3.	Point-snap the pivot point for each icon to the joint it will control.
4.	Select the left breast icon, then the corresponding joint, and do a point constraint. Do the same for the right breast icon, constraining the joint to the icon.
5.	You now have icons that let you animate each breast individually. We also want to be able to animate them both at the same time. To set this up, select both icons and group them, calling the new group BreastControls. Center the pivot of the group by going to Modify > Center Pivot.
6.	As seen in Figure 12.71, right, make the display handle visible (Display > Component Display > Selection Handles).
7.	Parent the BreastControls group to the Upper_Spine icon so that the group will move with her upper body.

We now have the option to animate both breasts at the same time by using the BreastControls group, or move them individually via their icons.

Hair and Wings

The final areas we need to rig are Kila's hair and Grae's wings. You should by now have a good grasp of the tools that are available to help you rig these areas, so take a stab at it yourself and see what you can come up with. If you have trouble or are struggling with something, you can always refer to the files called Kila_XtrasRig.mb and Grae_XtrasRig.mb on this book's CD.

Ideally, a dynamics engine will drive animation of Kila's hair. This would provide the best results and free up the animators to work on other things. Unfortunately, we don't have that luxury for Kila, so take the opportunity to try and add your own, simple rig.

Here are a couple of suggestions:

You might give the hair a very basic rig, forcing the animator to supply every movement the hair needs. Simply implement some basic icons that will control the hair joints' rotations. This approach has its advantages, since there will be occasions where the animator needs complete freedom over the way the hair moves.

You can use IK handles to control each joint. This technique allows you to pull the hair around from the baseit's a more user friendly way of animating.

Rigging Grae's wings can be approached in a much easier way: Import the file Icon_Wings.mb into the scene. You will find that I have already set up a series of attributes on the icons for you to use. Then use Set Driven Keys to generate poses for the wings, which correspond to each attribute.

Both Kila and Grae's bodies are now fully rigged, head to toe (Figure 12.72). The only other main controls we need to add are those to control facial animation, which we will discuss in the next chapter.