FBIK animation keys use the special stepped next tangent type by default. This tangent type differs from regular stepped tangents in that its interpolation values jump immediately to that of the next key, rather than holding the value of the current key until the next key is reached. This tangent is useful because it lets you key your character’s FBIK effectors as you manipulate them, so that you do not have to plan your animation ahead or think about what is the right effector to select and manipulate to get your character into its next pose. You do not have to actively manage your FBIK animation curve tangency, as the automatically done by the FBIK system.
For example, if you used regular stepped tangents for a walk cycle that you are animating with FBIK, you would have to set keys on each joint and FBIK effector that translates or rotates as it moves from one pose to another (such as the rotations of the auxiliary pivots at the heels of your character’s feet or the translations of the effectors at your character’s ankles). But if you used stepped next tangents for the same FBIK animation keys, you would only have to set keys on your body parts once for each pose, not each individual FBIK effector or joint.
FBIK keys in the Time Slider, Graph Editor, and Dope Sheet
You can edit the positions and timing of your FBIK keys with the Graph Editor and Dope Sheet. However, when you need to view or delete your FBIK keys, use the Time Slider.
Deleting your character’s FBIK keys from the Time Slider—not the Graph Editor—keeps your character’s IK and FK skeletons synchronized during its animation interpolation. Keeping your IK and FK skeletons synchronized is essential to creating good, desirable FBIK animation results. You can delete your FBIK keys from the Time Slider with the Delete FBIK Keys menu in the Time Slider context sensitive menu. See Animation controls menu.
When you select a keyed FBIK effector or input joint, only its keys display in the Time Slider, Graph Editor, and Dope Sheet by default. However, when Skeleton > Full Body IK > Body part Autoload is on, the current Key Mode determines which keys display. For example, when in All Key Mode, all the FBIK keys (IK and FK) for the selected FBIK effector or input joint’s character display. When in Body Part Key Mode, the FBIK keys for all the FBIK effectors and input joints for the selected effector or joint’s body part display. And when in Selected Key Mode, only the FBIK keys on the selected FBIK effector or input joint display.
