2009

Because pivots are located in all extremes of the hands and feet, their
trajectories discontinuous when both FK and IK periods are employed. The
following figure shows a simple example of this. During the planted IK periods,
the pivot trajectories show just the keys on the heel and toe (because the keys
are planted, each pivot stays in place), and during the FK periods the
trajectories are derived from the foot’s node pivot location. This gives you
more-detailed information about the animation that is driving the foot.
Footstep trajectory
In following illustration, while the biped walks, the right hand reaches up to
touch something in IK, as shown by the yellow trajectory, made by two sliding
IK keys. Later, the biped touches its own face, using body space IK, as shown
by the bright blue keys. The color transition in the trajectory from purple to
blue indicates a changing blend from FK to body-space IK, showing the
interpolated value of the IK Blend parameter.
Biped User Interface | 4469