Inverse kinematics is often shortened to IK, and it's highly important for achieving easy and believable character animation. Practically, IK lets you position hand or feet bones in a rig, and the remaining joints and bones will rotate and move automatically to achieve a believable look. In other words, for creating walk animations or pick-up animations, where a foot or hand comes in contact with a surface, IK saves the effort of animating all the bones involved, between either the foot and the hip, or the hand and the shoulder.

Configuring IK in Blender

Most 3D applications, such as Maya, 3ds Max, and Blender, provide options and features for creating IK. The purpose of these features is to help artists make animation simpler and easier. However, different programs store IK data differently, and this data is not typically transferable into Unity, even via FBX Files. This means that your character models will almost always be imported without IK data. This, however, doesn...