Rigging for Realistic Movement - Game Character Creation with Blender and Unity - page 161

Figure 7.5
Image of a single
bone. The head/root
is the sphere at the
thick end and the
tail/tip is located at
the thin end.
Figure 7.6
Rotating an arma-
ture's spine (the
parent) forces its
children (the arms
and head bones) to
follow.
Beyond their default relationships, bones can also be set up to have constraints in the
way they move. These constraints open up a wide variety of possibilities for posing and
animation, such as having bones follow or point to one another. One of the most impor-
tant constraints is inverse kinematics (IK). IK allows the bone at the end of a chain of
bones to control the entire chain (Figure 7.7).