Character Rigging - Game Character Development with Maya - page 700

Iconsdon'tjusthelpwithnavigation; theyalsohelpwithpositioning.Alljointshavetrans-
lation values on them that cannot be frozen, and resetting them to zero will position each
joint at the world root. Having icons drive the joints with an initial value of zero is useful
if you need to reset the character or copy animation from one icon to another.
Another valuable asset is that you can add dynamic attributes to these control icons. A dy-
namic attribute added to the icon can then control a series of other attributes on a com-
pletely different object; this is done using the Set Driven Keys command under the Anim-
atemenu(whichwewilldiscusslaterinthechapter).Forexample,youcouldhaveasingle
attribute on the hand icon that will pose the entire hand, making it into a fist; a value of 0
on this attribute would be the hand in its default pose, and 10 would be the fist. As you can
imagine, animating the hand will go much more quickly using a dynamic attribute than it
would if you had to rotate each finger joint individually and then set a key.
All that said, Maya's selection handles still have a great deal of use in our rig and, when
used on a small scale, can prove invaluable.
Icon Creation
You can use anything, from locators to default curves, as icons—as long as you make it
easy to identify which area of the skeleton is represented. Having the same icon/locator
for each control would be just as confusing as using the default selection handle, as shown
earlier in Figure 12.1 , left.
Maya has some default shapes that you can choose for icons:
A plain circle shape can be created quickly by going to Create > NURBS Primit-
ives > Circle.
If you only want half of the circle, you can use Create > Arc Tools.
You can always use a locator from Create > Locator.
The default icon shapes are good solutions for quick iconic representation, but you may
need more specific shapes, too, such as feet or hands. To create these, you'll use the curve
tools found in the Create menu.
The Control Vertices (CV) Curve tool creates curves based on the placements of
control vertices (CVs). Each CV contributes to the overall shape of the curve.
As demonstrated in Figure 12.2 , the curve you build will not show up until you
have placed the first four CVs. You will also notice that the CVs don't lie on the
actual curve, so this method of creation is less helpful if you are making precise
shapes.