Rigging & animation · Intermediate
Forward kinematics
Posing a limb one joint at a time, from the shoulder down
Also called FK
What is forward kinematics?
Forward kinematics, or FK, is posing a chain of bones one joint at a time, from the top down. You rotate the shoulder, then the elbow, then the wrist, and each bone carries everything below it. It gives full control over arcs and is how bones move by default.
Think of it like this
Like moving your own arm on purpose: turn the shoulder first, then bend the elbow, then tilt the wrist, one joint after another.
Where it fits in a 3D project
- Create
- Surface
- Rig
- Animate
- Render
- Export
Rig: Adding a skeleton and controls so the model can move.
How forward kinematics works
- 01Bones are linked in a parent and child chain, such as shoulder to hand.
- 02You rotate the top bone, and the whole chain swings with it.
- 03You rotate each lower bone in turn to refine the pose.
- 04Keyframes store each rotation, and the software fills in the motion between.
Forward kinematics vs inverse kinematics
| Property | Forward kinematics | Inverse kinematics |
|---|---|---|
| You move | Each joint, from the top down | The end of the chain |
| Best for | Swinging arms, tails, follow-through | Feet on floors, hands on objects |
| Planted contacts | Hard, the end drifts | Easy, the end stays put |
Use FK for free, swinging motion and IK when a hand or foot must stay locked to something.
Where forward kinematics is used
- Arm swings in walks, runs and throws
- Tails, tentacles and spines that flow in arcs
- Quick rough poses while blocking out a shot
Beginner tip
Animate arms in FK for gestures and throws, and switch to IK only when the hand must touch something. Arcs come out smoother, with less fighting the solver.
Terms related to forward kinematics
- Rigging & animationInverse kinematicsPosing a limb by moving its end, like dragging a hand into place
- Rigging & animationBoneOne rigid piece of a 3D skeleton that moves the mesh around it
- Rigging & animationSkeletonThe full set of linked bones that decides how a 3D model can bend
- Rigging & animationControl rigThe handles animators grab to pose a character without touching bones
- Rigging & animationRiggingGiving a model a skeleton and controls so it can be posed
- Rigging & animationKeyframeA saved pose or value at a point in time; software fills the gaps
Forward kinematics FAQ
Updated October 29, 2026 · Browse all 3D terms