2009

Initial State group
When you first create a hierarchical chain, the initial position of the bones
or objects is the initial state. The options here let you display, alter, or lock the
initial state. When both of the options here are turned off (the default),
transforming the end effector is different from transforming the other joints
in the chain. When you select and transform a joint assigned an end effector,
you are actually transforming the end effector, and an IK solution transforms
the joints. This alters the position of the bones or objects in the viewport, but
will not alter their initial state. On the other hand, when you select and
transform any of the joints without end effectors, you alter their initial state.
Show Initial State Shuts off the real-time IK solution. All objects in the chain
are moved to their initial positions and orientations prior to any changes
caused by IK calculations. The positions of the end effectors, however, are not
affected.
Turn on Show Initial State to view the initial state, or adjust the initial state
of bones or objects using end effectors. This is useful when you set joint limits
using the IK controls in the Hierarchy panel: the joints jump to their limits
while you set them. When Show Initial State is off (the default), you can select
and alter the initial state of bones or objects without end effectors, but when
you select a bone or object with an end effector, the end effector is transformed,
leading to an IK solution; the initial state of the associate object is not changed.
By selecting this, you can transform the initial state of the associated object.
Lock Initial State Locks all bones or objects in the chain from direct
transformations. You can, however, transform the end effector of any joint
to generate the IK solution without altering the initial state. Activate this when
you want to avoid accidentally selecting and transforming joints that are not
assigned end effectors. When Show Initial State is selected, Lock Initial State
is ignored.
3428 | Chapter 15 Animation