Notes on Animation Tutorial 3: Creating a Basic IK system
Tools used in this tutorial
Joint Tool (Animation)
You can get the options by going to and hitting the hitting the options box, or by double clicking the icon in the shelf
IK Handle Tool (Animation)
Locator (Animation)
A Locator in Maya is what in all other 3D software is called a Null or Null Object.
Notes
Note how the bones are created at an angle from each other, the joint is "bent". This is essential for the software to understand how you want the bone chain to bend
Create an IK Handle: To see the bones inside the object as dispayed here, turn on X-ray shading
Left to Right: XRay, XRay Selected and XRay Bones.
To make selecting bones easier turn on Xray Bones
Pole Vector: If the pole vector constraint fails [//Error: line 0: Handle must be valid and use rotate plane solver] you need to change the IK solver to Rotate Plane Solver. Either before applying IK (creating the IK handle) or in the attribute editor.