Retargeting is the process of applying an animation from one character to another. If your character is auto-rigged, you usually want to reuse existing animation packs (walk/run/idle/combat) without reanimating everything from scratch.
Why retargeting sometimes looks bad
Most retargeting problems come from:
- different base poses (T-pose vs A-pose)
- different proportions (very long arms/short legs)
- twisted joint orientations
- bad skin weights around shoulders/hips
Unity retargeting (Humanoid)
Unity's Humanoid system can retarget animations between characters if the avatar mapping is correct.
- Import your rigged character FBX.
- Set Rig → Animation Type → Humanoid.
- Configure avatar mapping and fix missing bones if needed.
- Import animation clips and set them to Humanoid.
- Apply clips to your character Animator Controller.
Unreal retargeting
In Unreal, retargeting uses skeleton/IK rigs depending on engine version and workflow. The core idea is similar: define a mapping and reuse animations across compatible rigs.
Best practice for predictable retargeting
- Use a consistent T-pose for all characters
- Keep scale and proportions within reasonable bounds
- Avoid extreme shoulder/hip offsets in the base mesh
- If needed, polish weights on shoulders and hips
If you're building a character pipeline, the fastest path is: auto-rig in T-pose, export engine-friendly FBX, then retarget animations inside the engine.