2009
Terminating Chains (HD Solver)
The kinematic chain is automatically defined using the object you select as
the end effector and working up the hierarchical tree to use the root object
as the base of the kinematic chain. Sometimes you might not want the
kinematic chain to go all the way to the root of the hierarchy. This is especially
true when you are animating multi-limbed or branching structures, such as
an octopus or a tree.
Terminator option in the Object
Parameters rollout
You use the Terminator option in the Object Parameters rollout to stop
calculation of the kinematic chain before it reaches the root object of the
hierarchy. A terminator object stops calculation at the terminator's child
object; the terminator itself is not affected by the IK solution. This gives you
very precise control over the behavior of the kinematic chain.
For example, look at the bird in the figure. The bird is linked with its body as
the root of the hierarchy. If you use inverse kinematics to move the duck, all
objects from the duck to the body will be affected by the IK solution. However,
if you define a neck bone as a terminator object, then only the objects from
the duck to the neck vertebrae are affected.
3442 | Chapter 15 Animation