Forward Kinematics
The art of rotating bones one at a time. Old school. Precise. Meditative.
What is Forward Kinematics?
Forward Kinematics (FK) is the traditional approach to skeletal animation. You select a bone, rotate it, and every child bone follows along. Want to raise an arm? Rotate the upper arm, then the forearm, then the hand. Each joint is under your direct control.
It's called "forward" because you work from the root of the skeleton outward to the extremities — parent to child, shoulder to fingertip. The opposite approach, Inverse Kinematics, lets you grab the end and the solver figures out the joints. Both have their place.
FK is great for
- Arcs and sweeping motions
- Overlapping action (follow-through)
- Precise per-joint control
- Spine and torso animation
- Refining retargeted animations
IK is better for
- Planting hands/feet in place
- Quick posing and blocking
- Reaching for objects
- Maintaining contact points
- Legs and ground interaction
Selecting Bones
Press S to enter Select mode. Now click any bone in the viewport or the bone list in the right panel. The selected bone highlights and its transform values appear.
Mirror Selection
Press M to select the mirror of your current bone. If you have LeftUpperArm selected, pressing M jumps to RightUpperArm. Essential for symmetric poses.
The right panel shows the full bone hierarchy. Click the arrows to expand/collapse groups. You can select bones there too — useful for finding deeply nested bones like fingers.
Rotation Mode
Press R to enter Rotate mode. Three colored rings appear around the selected bone:
- Red ring — X axis rotation
- Green ring — Y axis rotation
- Blue ring — Z axis rotation
Drag a ring to rotate the bone around that axis. The rotation values update in real-time in the right panel. You can also type exact values into the numeric fields for precision work.
Translation Mode
Press T to enter Translate mode. RGB arrows replace the rings:
- Red arrow — X axis movement
- Green arrow — Y axis movement
- Blue arrow — Z axis movement
Translation is mainly used for the root bone (Hips) to move the entire character. Moving non-root bones stretches the mesh and is usually not what you want — unless you're going for that surreal aesthetic.
Translating bones other than the root/hips will deform the mesh in unexpected ways. Stick to rotation for posing limbs and joints. Translation is for repositioning the whole character.
Keyframing
Animation is built from keyframes — snapshots of bone positions at specific points in time. The timeline at the bottom of the screen is where the magic happens.
Autokey Mode
Look for the Autokey button in the timeline. When it's active, every bone rotation or translation you make automatically creates a keyframe at the current frame. This is the fastest way to animate — just scrub the playhead, pose, scrub, pose.
Manual Keyframing
Prefer more control? With Autokey off, pose your character however you like, then click the + Key button to manually record keyframes at the current frame.
The Timeline
The timeline lives at the bottom of the screen. It's resizable — drag the top edge to make it taller or shorter.
Playback Controls
| Control | What It Does |
|---|---|
| Play / Pause | Toggle animation playback |
| Stop | Stop and return to frame 0 |
| Playhead | Drag to scrub through the animation |
| Frame counter | Shows the current frame number |
| Autokey | Auto-create keyframes when you transform bones |
Keyframe Tracks
Each bone with keyframes gets a track in the timeline. Keyframes appear as small diamonds or dots. Click a keyframe to select it, then delete it with the delete button if needed.
Copy & Paste Keyframes
One of the most powerful workflow shortcuts:
| Shortcut | What It Does |
|---|---|
| Ctrl + C | Copy the selected bone's keyframes at the current frame |
| Shift + Ctrl + C | Copy ALL bones' keyframes at the current frame (full pose) |
| Ctrl + V | Paste copied keyframes at the current frame |
Want a perfect looping animation? Copy the pose from frame 0 (Shift + Ctrl + C), scrub to the last frame, and paste (Ctrl + V). Now frame 0 and the last frame are identical — seamless loop.
Undo & Redo
Ctrl + Z to undo. Ctrl + Y (or Shift + Ctrl + Z) to redo. The undo history is generous — experiment fearlessly.
The undo/redo buttons are also in the header bar if you prefer clicking.
Animation Tips
Professional animators always start with the root. Set the overall body position and weight distribution first, then work outward to spine, arms, legs, and finally fingers and head. Center of gravity first, details last.
For symmetric poses (standing, idle, etc.), pose one side, then use M to jump to the mirror bone and match the opposite side. Saves half the work.
Don't try to nail the final animation in one pass. First, create "key poses" at major beats (contact, passing, down, up for a walk). Then add in-between poses. Then fine-tune timing. This is how the pros do it.
If you imported a Mixamo animation via retargeting, FK is perfect for refinement. Scrub through the animation, find frames that need tweaking, and adjust individual bones. The retarget gives you 90% — FK gets you to 100%.
What's Next
Inverse Kinematics
Grab an end effector and drag. The solver handles the joints. Perfect for posing and contact animations.
Explore IK →Animation Retargeting
Why animate from scratch? Import existing animations and retarget them to your character in seconds.
Learn retargeting →Export Your Work
Ship it. Export as optimized GLB, or use the Blender pipeline for further editing.
Export options →