This advanced technical rigging course covers the math and modular logic required to build a production-grade biped limb system inside Unreal Engine’s Control Rig, guiding you step-by-step through creating reusable FK/IK functions, pole vector constraints, and dynamic space-switching pipelines.
https://dev.epicgames.com/community/learning/courses/qve/unreal-engine-control-rig-biped-ik-fk-limb-setup