Rigging & Posing
A rigged model has a skeleton: bones that its mesh follows. In the Animation workspace you give a model a skeleton in Rig mode, check and paint how its mesh follows the bones in Skin, and pose and key it in Animate, all on the stage.
Giving a model a skeleton
Put the model on the stage (pick it in the stage's dropdown, or select it in the scene). A model with no skeleton opens in Rig mode.
- Stand the character in a T or A pose (the model as imported).
- In the left panel, choose Humanoid.
- Click Place Points, then click the model at each point in turn: chin, shoulder, elbow, wrist, groin, knee, ankle. One side is enough; the other is mirrored, and its points show faded. Click a point's row to place it again;
Escstops. - Once all seven are placed, the stage shows the skeleton they will build, dashed.
- Click Generate Skeleton.
The skeleton has Mixamo's bone names and orientations, so Mixamo clips, and any clip made for a Mixamo rig, play on it as they are. The skin weights are generated by distance to each bone; fingers are not rigged, so a hand moves as one piece.
The model's file is rewritten with the skeleton and skin in it, and every copy of it in your scenes updates. The original is kept beside it as <name>.unrigged.glb, and Remove Rig puts it back. Rigging again always starts from that original.
For a head, choose Face instead: see Facial Animation.
Reading the skeleton
The right panel lists the skeleton as a tree. Click a bone there or on the stage to select it; the Bone tab shows its name, its parent, its length and its partner on the other side.
Skin: how the mesh follows the bones
Switch to Skin to see and paint the weights: how much each bone moves each part of the mesh. The model turns into a heat map of the bone being painted, dark blue where it has no pull through to red where it has all of it. Nothing shows on the scene's model until you save.
- Auto Weights weights every vertex by how close it is to each bone. Smooth blends across the mesh; Sharp keeps hard edges between bones.
- The brush paints the chosen bone. Pick the bone in the Paint Bone list, or Ctrl+click it on the model.
| Brush | Does |
|---|---|
| Add | Pulls the vertices towards the bone |
| Remove | Pushes them off it, onto the bones around |
| Smooth | Evens the weight out with the vertices around it |
| Set | Sets it to the Strength exactly |
Radius is a share of the model's size, Strength how hard each stroke presses, and Falloff how it fades to the brush's edge. Mirror strokes paints the other side's bone at the mirrored spot at the same time. Each stroke is one undo step.
- Test bends the painted bone with the Bend sliders, or Range of Motion swings every joint, so you see the weights working as you paint. You paint the mesh as it is bent. Only the stage moves; nothing is keyed.
- Checks counts vertices no bone moves and vertices whose weights do not add up to 1; Normalise fixes the second.
- Save Weights writes the weights into the model file and reloads it everywhere. Leaving Skin saves anything painted; Revert throws it away.
Weights are saved straight into the .glb. A model the engine had to rebuild on load (one without normals, which gets flat ones by splitting its vertices) cannot be saved this way; the Console says which mesh.
Posing a bone
In Animate, click a bone on the stage. A bone is drawn from its joint to the next, and belongs to the joint it turns around, so clicking the forearm selects the forearm. Shift+click adds a bone to the selection.
- Turn it:
E, then drag a ring. The white ring turns it about the view. - Move it:
W, then drag an arrow, or the centre square to move it in the plane facing you. - Local or World in the header sets whether the gizmo follows the bone's own axes or the world's.
- The Pose tab on the right has the selected bone's turn as three sliders.
Each drag is one undo step.
A pose lasts until the playhead moves
While a clip is playing in the timeline, each frame of it sets the bones it animates. A pose you make sits on top of that until you key it or move the playhead, then it is dropped and the clip's pose shows again, the same as in other animation tools.
Keying
Press K with the cursor over the stage or the timeline, or Key Pose in the Pose tab, to key every bone you have posed and every selected bone at the playhead. A bone with no track in the clip gets one. The key plays at once; the clip file is saved a moment later.
With Auto key on (the chip on the stage, or Record in the timeline), every change you make to a bone is keyed as you make it.
Bone keys go to the bone's own track whether you key from the stage, the Pose tab or the Inspector's keyframe button.
Pose tools
These act on the selected bones, or on every bone when none is selected.
| Tool | What it does |
|---|---|
| Reset to Rest | Puts the bones back in the pose the model was rigged in |
| Mirror | Copies each selected left bone's pose to the right one, or the other way round |
| Flip Pose | Swaps the whole pose left for right, the other half of a walk |
| Copy / Paste | Takes a pose from one frame to another |
| Paste Mirrored | Pastes the copied pose flipped left for right |
Mirroring works from each bone's rest pose, so it is right for any rig whose two sides mirror each other, whatever way its bones are pointed. Left and right bones are paired by name: LeftArm/RightArm, arm.L/arm.R and arm_l/arm_r all work.
The pose library
The Controls tab's Pose Library keeps whole poses by name. Type a name and Save Pose saves the pose on the stage; click a saved pose to put it back (on the selected bones, or all of them), and key it as usual. Poses are files in the project's animations/poses/ folder, one .pose each, so every scene shares them, and a pose made on one Mixamo character fits any other.
IK
Inverse kinematics makes an arm or a leg reach. The Limbs section lists the rig's limbs (each hand or foot with an elbow or knee above it). With a limb's IK on, move its hand or foot (W) and the elbow or knee bends so the hand stays on the end of the arm, instead of the wrist stretching away. The bend stays in the plane the limb already bends in, so an elbow never flips. Key the result as usual.
Two copies of the same character
Entity names in a scene are unique, so a second copy of a model gets mixamorig_hips_1 where its clips say mixamorig:Hips. Animation binds through the name the bone had before the editor made it unique, so both copies play their clips.