2009

An IK solver places keyframes only on the IK goal or end effector, as opposed

to forward kinematics (or the non-solver IK methods), which place rotation

keyframes on the bones or hierarchical objects themselves.

Other IK Methods

In addition to the IK solvers, 3ds Max provides 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 carried over from the earliest versions of the

software. It is generally recommended that IK Solvers be used in most cases rather

than Interactive or Applied IK.

■

Interactive IK on page 3459

Interactive IK gives you the ability to use IK manipulation on hierarchies

without applying an IK solver. You animate your IK structure 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 calculated only for the keyframes you set. All other motion

is interpolated as set by the object's controllers. Moving the end of 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 the tools in the

Auto Termination rollout on page 3499.

■ Applied IK on page 3462

With Applied IK, you animate follow objects and the program calculates

the solution on every frame of a specified range. The IK solution is applied

as standard transform animation keys. 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 kinematics on the

same objects. You can 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.

Inverse Kinematics (IK) | 3381