8

IK Solvers 421
rotation key frames on the bones or hierarchical
objects themselves.
Other IK Methods
In addition to the IK solvers, 3ds Max pro vides
two non–solver methods of inverse kinematic
animation: Interactive IK and Applied IK. These
IK methods do not apply an IK solver.
Note: These are older IK methods car ried over
from the earliest versions of the software. It is
general ly recommended that IK Solvers be used in
most cases rather than Interactive or Applied IK.
•
Interact ive IK (page 2–462)
Interactive IK gives you the ability to use IK
manipulation on hierarchies without applying
an IK s olver. You animate your IK str uc ture
by activating Interactive IK (found in the
IK panel of the Hierarchy panel and on the
Hierarchy toolbar) and manually animating
the position of end effectors. IK solutions
are c alculated only for the keyframes you set.
All other motion is interpolated as set by the
object’s controllers. Moving the end o f the
chain simply adds rotational keys to the objects
in the chain. The objects can have joint limits
assigned, for additional control. The chain can
also be terminated using t he tools in the
Auto
Termination rollout (page 2–481)
.
•
Applied IK (page 2–464)
With Applied IK, you animate follow objects
and the program calculates the solution on
every f rame of a specified range. The IK
solution is applied as standard transform
animation k eys. Applied IK works with any
linked hierarchy of objects except for bones
that use the HI Solver or the IK Limb Solver. It
can combine forward kinematics with inverse
kinematicsonthesameobjects. Youcan
apply it automatically to a range of frames, or
interactively to single frames.
Applied IK is fast and accurate, but it creates
keys for every object in the kinematic chain,
on every frame. The large number of keys
can make it difficult to adjust the animation
later. Use Applied IK repeatedly to adjust the
animation.
IK Solvers
Select an object in a hierarchy where you want IK to start.
> Animation menu > IK Solver > Apply an IK solver. >
Click the object in the h ierarchy where you want the IK
chain to e nd.
An IK solver creates an inverse kinematic solution
to rotate and position links in a chain. It applies
an IK Controller to govern the transforms of the
children in a linkage. You can apply an IK solver to
any hierarchy of objects. You apply an IK solver to
a hierarchy or part of a hierarch y using commands
on the Animation menu. Select an object in the
hierarchy, choose an IK solver, and then click
another object in the hierarchy to define the end of
the IK chain.