8

Animating with the HI IK Solver 427
•SplineIKSolverforimprovedcontrolof
intricate, multiple-bone structures
4. Click where you want the IK chain to end.
If you are using the IK Limb Solver , you must
applytheIKSolvertocontrolonlytwobones.
TheIKsolverappearsintheviewport.
To create a bones hier a rchy that uses a n IK solv er:
1.
GototheCreatepanel,choose
Systems, and click Bones.
2. In the IK Chain Assignment rollout, select an
IK solver from the list.
3. Turn on Assign To Children.
4. Click and drag in a viewport to create the
bones. Right-click to stop bone creation.
The bones are drawn with the IK solver already
applied.
Note: IfyouusetheSplineIKSolver,aSplineIK
Solver dialog will appear w here you can make
special settings for the spline and helpers used
by the Spline IK solver.
Todisplayahierarchyofobjectsasbones:
1.
Select the hierarchy of objects in the viewport.
2. On t he Character menu choose Bone Tools.
3. Expand the Object properties rollout.
4. In the Bone properties group, turn on Bone On.
5. On the Display Panel, scroll down to Link
Display and expand it.
6. On the Link Display rollout, turn on Display
Links, and Link Replaces Object.
The objects disappear and the lin ks are
displayed as bones.
Histor y -I ndependent (HI) I K
Animating with the HI IK Solver
The HI (History-Independent) Solver does
not rely on IK solutions calculated in previous
keyframes in the timeline, so it is just a s fast to use
at frame 2000 as it is at frame 20.
The HI Solver uses a goal to animate a chain. You
animate the goal and the IK solver attempts to
move the end effector (the pivot point of the last
joint of the chain) to match the position of the
goal. Often the goal is parented to other control
objectssuchaspointsordummies,splinesor
bones, and these control objects in turn are wired
to viewport or rollout sliders.
TheIKsolutiontakesplaceinaplane,knownas
the
solver plane . The angle of the solver plane in
world space is controlled by a p arameter called
the
swivel angle (page 2–430) .Theswivelangle
isanimatable.Youcanadjustitdirectly,orwith
amanipulator.
The HI Solver allows for the creation of multiple
or overlapping chains. This allows you to create
multiple goals for additional controls. By linking
the goals to points, splines, bones or dummies,
you can create simple controls to animate complex
chains or hierarchies. You can also use constraints
on these goals or control objects, as another
animation tool.
Applying an HI Solver
To a pply a n H I S olve r t o a ny p a r t of a h i e r a rchy
selecttheboneorobjectwhereyouwanttothe
solver to start. Then choose Animation menu > IK
Solvers > HI Solver . In the active viewport move
your cursor to the bone where you want the chain
to end. When you click to select that bone, the
goal is drawn at the pivot point of that bone. If