Graphics Reference
In-Depth Information
Testing Your Rig
When the rig is created and deformers are set up, you need to test the entire contraption. The best way to do
it is to pick the most demanding scene from your story reel and put your character through its paces. Actions
to watch out for that will show shortcomings in your rig are as follows:
Any time a character (or a part of a character) rotates more than 180 degrees from its initial position, or
even worse, past 360 degrees: Think a backfl ip or a character pacing around in a circle. Sometimes joints
and bones will “fl ip” or “pop” at those points, creating bad breaks in animation. These kinds of prob-
lems can be identifi ed early on, even during the B-Bone visualization stages before a mesh is attached.
If you are only fi nding these problems after you've carefully bound and weighted your high resolution
character mesh, you probably should have done more “real life” testing with keyframed animation sooner.
Usually these problems stem from using Tracking constraints incorrectly or from inadequately restricted
IK joints.
Limbs that move very close to the body: This will show deformation problems because limbs or cloth-
ing might intersect with each other at the nearest limits of what the rig can handle. Of course, if these
intersections don't occur where the camera will see them, you can put fi xing them on your list of things
that may be nice to get to
some day. Another problem
when limbs move close to
the body is that the body
actually pulls away from the
approaching limb. Figure
9.47 shows this effect. In
cases like this, you will need
to work on the deforma-
tions. Almost certainly, arm
or shoulder bones are infl u-
encing vertices that control
(either directly or indirectly)
the parts of the body that
are moving incorrectly.
Eliminate their infl uence on
those portions of the body
in Weight Paint mode.
Limbs or bone chains that
extend toward their outer
limits: While problems generated by stretching a rig beyond its capacity are generally solved by ani-
mating carefully so that it simply doesn't happen, limbs and joints will sometimes pop into a reversed
position at extremities. This is just one of the limits of the IK solving process. When the chain is fully
extended, the bones “lock” into place until the IK target comes back within reach of the chain. Your
only friend here is knowing the limits of your rig and animating appropriately.
Figure 9.47
An arm moving close to the body, causing the ribcage to shrink
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