Avatars
The Avatar view of the Body tab assigns the character that tracking data drives.
Assigning one
Set Avatar Prefab to a humanoid character prefab. The tracked pose is applied to it every frame.
A prefab works if Unity recognises it as a humanoid rig — that is, it was imported with the animation type set to Humanoid and has a valid Avatar configured. Characters from Mixamo, Ready Player Me, and most humanoid asset-store rigs qualify without extra work.
The Body tab validates the prefab when you assign it and tells you if the rig is not usable, rather than failing silently at runtime.
Why a humanoid rig
Unity's humanoid system maps any conforming rig onto a standard set of bones. Because tracking data is applied through that standard set rather than to bone names directly, a rig with different proportions, a different bone naming scheme, or a different number of spine joints still works — Unity handles the translation.
The practical consequence: you can swap characters without reconfiguring tracking. If a character does not move at all, the first thing to check is whether its import settings say Humanoid.
When the avatar looks wrong
Work out which side of the boundary the problem is on before changing anything.
- Turn on Gizmos → Joints and Bones. You now see the tracked pose independently of the avatar.
- Compare.
| Gizmo skeleton | Avatar | Where the problem is |
|---|---|---|
| Correct | Wrong | The avatar rig. Check it imports as Humanoid; check its axes in Avatar Calibrations. |
| Wrong | Wrong | The tracking source. Check the provider settings and Tracking Calibrations. |
| Correct | Correct but offset in the room | Fusion origin alignment, or the tracking space — see Fusion. |
Set the provider to Synthetic and watch your avatar. Synthetic produces known-good motion with no hardware involved, so anything wrong with the character at that point is the rig — you have removed the tracking source as a variable entirely.
Proportions
Tracked skeletons and avatar rigs rarely have the same limb lengths. Unity's humanoid retargeting handles the difference, but a large mismatch shows up as hands not quite reaching where the participant reached.
Two settings help:
- Bone length on the tracking row scales the tracked skeleton toward the participant's actual proportions.
- Offset (m) under Fusion's Leg Driver corrects standing height, including shoe thickness.
For reaching and grasping tasks, where hand position matters more than a smoothly continuous arm, Pin Hands To Tracked Wrists under Fusion forces the hands to the tracked wrist positions.
Fusion avatars
If you are using Fusion, right-click an avatar prefab in the Project window and choose LABO → Create Fusion Avatar Prefab. This produces a variant already set up to be driven by a fused upper and lower source.