2009

position. It generally is not perpendicular to the viewport. Therefore, we
will see a flip once it takes a new Start Joint.
If you delete the solver/goal and assigned a new one from Bone02 to Bone04,
you will find that the chain won’t flip. Why? Assignment of Start Joint is
different from creating a new IK chain/goal. Start Joint is one of many IK
parameters. Reassigning it is simply the same as modifying any parameter.
The rest parameters are intact. In particular, the Swivel Angle is not changed
as a result of this reassignment.
Creating a new IK chain/goal is different. Effort is made to ensure that the
joint chain stay fixed by adjusting parameters appropriately. In particular, the
Swivel Angle will be set to a value so that the solver plane keeps stationary in
the viewport.
HI IK Solver Rollouts (Motion Panel)
IK Solver Rollout (HI Solver)
Select an HI or IK Limb Solver IK Chain control (the blue cross at the end of
the chain.) > Motion panel > Parameters button > IK Solver rollout
The HI Solver is a history-independent solver that doesn't rely on the
calculations from previous frames for the IK solution, so it is fast to use no
matter the length of your animation. The history-independent solver uses a
goal to manipulate the end of the chain. It uses a preferred angle that specifies
a preference regarding which direction the link will rotate: positive or negative.
The preferred angle can also be considered as the initial angle; that is, the
angle at which the link was rotated at the time the solver was applied.
The IK solution takes place in a plane, known as the solver plane. The angle of
the solver plane is controlled by a parameter called the swivel angle.
Inverse Kinematics (IK) | 3407