Posted on Nov. 5, 2020, 9:35 a.m. by crute • Last updated on Nov. 5, 2020, 11:21 p.m.
This stutter is the result of the solver going through the iterations and having to correct the parent position after every move of the child.
This video explains the problem and how to find and fix them quite nicely: https://youtu.be/NDlO48ai9FU
The Default value of 0 will make all bones up the chain part of the IK, until it reaches a disconnected one.
The Pole Target Bone is usually extracted by extrusion from an IK-Chain Bone, just make sure to unparent it from the IK-Chain, if you go that way. You probably want to still keep it parented to your armatures the Root Bone.
Simply introduce a minute amount of bend by moving one of the bone heads in Edit Mode and the IK-Solver will behave much better.
The "Pole Angle" Input Field will only appear in the constraint once you have given it an actual Pole Bone. If your bones are aligned to world axes the pole angle values should be multiples of 90°. If you want to automate your rig a lot, it can be advisable to not use the pole angle adjustment but to set the chain's bone roll in such a way that the X-Axis points towards the pole. This will make the driver expressions a lot simpler.
For a more sophisticated setup, follow this LevelPixelLevel tutorial: https://youtu.be/suP14lYWpN8