One of the things that is absolutely essential for character animation is the ability to switch back and forth between IK and FK — an IK FK Switch.
Easily switch between IK and FK using the snapping tools of Duik IK/FK in After Effects
Nicolas Dufresne has been posting little tidbits on what is in store for the next release of DUIK. The latest posting shows the addition being the valued IK FK Switch.
If you are not familiar with the terms, animation rigs will typically allow you to either affect individual elements or elements as a group.
You can either rotate individual elements in a hierarchy, (known as forward kinematics, FK), or affect the entire chain by moving a single handle (known as inverse kinematics, IK).
— Duduf (@NicoDuduf) March 10, 2016
Both IK and FK have their advantages depending on the animation task at hand. This is why more advanced systems will allow you to switch between the two methods at will, with an IK FK Switch.
It also becomes important to be able to snap back to the orphaned IK handle, seamlessly, in an animation. This is why IK FK Switches will typically have some sort of snap incorporated with them.
In the video, Nicolas Dufresne shows off the new IK FK Switching system for DUIK 16, and it is looking rather good!