Animation retargeting: what changes between rigs
Animation retargeting transfers motion from a source skeleton to a different target skeleton. A reliable pass starts by matching the rest pose, root and hip semantics, bone hierarchy, scale, and joint orientation. Retargeting does not repair poor skin weights or guarantee clean foot contact; inspect representative clips after the transfer.
Retarget animation in Blender
For Blender retargeting, import the source motion, identify corresponding source and target bones, align the rest poses, then bake the constrained result onto the target rig. Mixamo, Rokoko, and BVH sources often use different bone names and axis conventions, so treat an add-on as a mapping aid rather than proof that the result is correct. Check root motion, hands, feet, shoulders, and fast turns after baking.
Mixamo, Rokoko, and BVH checks
Record the source frame rate, coordinate system, rest pose, and whether translation lives on the root or hips. With Mixamo or Rokoko data, confirm the expected character definition before mapping. For BVH, inspect scale and channel order. Keep the untouched motion file so mapping or cleanup decisions can be reproduced.
Retargeting for UE5 and Unity
In Unreal Engine 5, define the source and target rigs, align retarget poses, map chains, and preview several clips before export. In Unity, verify Avatar configuration and humanoid bone mapping before testing clips. In either engine, validate root motion, foot sliding, contact poses, and deformation in the final runtime rather than relying only on the DCC preview.