2009

Assume Pref Angles Copies the X, Y, and Z preferred angle channels of each

bone and places them into its FK rotation subcontroller. This essentially

performs the inverse operation of the Set As Pref Angles function.

Bone Joints group

Allows you to change the ends of the IK chain.

Pick Start Joint Defines one end of the IK chain. Select from the viewport or

by name (press H).

Pick End Joint Defines the other end of the IK chain. The direction of the

chain is defined by the hierarchy, not by Start and End Joint. Select from the

viewport or by name (press H).

WARNING If you change the Start or End Joints so the IK Limb Solver so there

are more than two bones between the start and end, the solver will not work.

Moving the IK goal does not affect the bones.

TIP The order of the hierarchy determines the direction of the chain. You cannot

reverse the direction of the chain by picking Bone 10 as the start and Bone 1 as

the end.

IK Solver Properties Rollout (HI Solver)

Select end effector of an HI IK chain. > Motion panel > Parameters button >

IK Solver Properties rollout

Here are the additional controls for the HI IK solver. The IK Solver Plane is

controlled here through the Swivel Angle, which can be animated directly or

using a target object.

In the Parent Space group you can choose to whether the IK goal or the start

joint will be used as the parent space for the swivel angle. If IK Goal is selected

(which is the default), then the Swivel Angle of the chain is defined in the

parent space of its goal. If Start Joint is chosen, then the Swivel Angle will be

relative to the parent space of the start joint. These two options allow a much

better control of the swivel angle on a chain with two HI IK solvers. For

example, the first solver on the upper part of a chain can use a Swivel Angle

in the Parent Space of the Start Joint, while the second IK solver on the lower

part of the chain uses the Parent Space of the IK Goal. In this case, the change

of the Swivel Angle for one chain won’t change the orientation of the other

one.

3412 | Chapter 15 Animation