Solver

Selects the solver to use for the chain’s IK.

• SOFTIMAGE|3D Solver maintains compatibility with chains imported from SOFTIMAGE|3D but may not be able to solve effectively if the chain has both stiffness and rotation limits.

• SOFTIMAGE|XSI Solver provides quicker results, but both solvers generally give the same results.

Solver Angles

Sets the method of calculating joint rotations based on the preferred angle.

• Use Preferred Rotations from Joint Properties calculates rotation values based on the joints’ preferred angles, so the joint rotations are always predictable.

• Use Joint Rotations changes the preferred angles if the joint angles are rotated manually. This is the same behavior as in SOFTIMAGE|3D.

• Reuse Joint Rotations at Every Resolution Step ignores the preferred angles and calculates rotation values based on the joints’ current angles. When the chain is extended to its full length, translating the effector toward the root will cause the chain to bend in one direction.

FK/IK Blend

Sets the blend weight between inverse kinematics (translation of the effector) and forward kinematics (rotation of the joint) on the selected chain. A value of 0 is 100% FK, while 1 is 100% IK (but still using the rotation on the bones as a preferred angle state).

For more information, see Blending Between FK and IK Animation in the Character Animation guide.

FK/IK Ghosting

Displays ghosts of the FK/IK values on chains when FK/IK Blend values are at 0 and 1. You must also activate Animation Ghosting and Skeleton FK/IK Ghosting in the view to see ghosting. You can set up the display on the Ghosting page in the Camera Display property editor.

Force IK

Triggers IK every time you modify the preferred angles from the Kinematic Joint property editor. This lets you immediately see the effect on the chain.

For more information, see Forcing the Effector’s Position in the Character Animation guide.

Type

Select the type of error threshold to use: Solver Default or User Defined.

Threshold

If you select User Defined, you can enter a value for the threshold. The value is in Softimage units, meaning that a value of 1 is a tolerance of one grid square.

As the Threshold value gets lower, it takes longer for the chain to solve. In fact, if the value is too low, the solver may not reach a solution and the effector won’t reach the IK goal.

Affected By Last Bone

Toggles on/off the effector’s dependency on the last bone. When on, the effector inherits the orientation of the last bone. When off, you can rotate the effector according to global coordinates.

Offsets

When Affected By Last Bone is selected, you can rotate the effector locally in X, Y, and Z with respect to the last bone.

Link with FK/IK Blending

Blends the effector’s orientation with the Blend FK/IK value (see above) to dictate how much of the “scene level” effector orientation is used relative to the rotation given by the last bone.

Inheritance Blend

Blends the effector’s orientation as taken from the last bone (plus any offset) against any other orientation affecting the effector, such as an orientation constraint on the effector.

The default value is 1, which fully constrained to the last bone’s orientation. A value of 0 (zero) is fully constrained to anything else affecting the effector’s orientation, which has the same effect as if Affected by Last Bone was off.