the Torque Variation Score

Distinguishing Imitation Error from Intrinsic Motion Learning Difficulty

arXiv:2512.07248v2 Announce Type: replace Abstract: Physics-based motion imitation is central to humanoid control, yet current evaluation metrics (e.g., MPJPE) only quantify imitation outcomes, not their underlying causes. This conflation obscures a critical diagnostic question: when imitation error occurs, does it stem from policy limitations or the intrinsic learning difficulty of the target motion? To resolve this ambiguity, we propose the Torque Variation Score (TVS), a physics-grounded...