Enhancing Hands in 3D Whole-Body Pose Estimation with Conditional Hands Modulator
Organizations: Korea University
Abstract
Accurately recovering hand poses within the body context remains a major challenge in 3D whole-body pose estimation. This difficulty arises from a fundamental supervision gap: whole-body pose estimators are trained on full-body datasets with limited hand diversity, while hand-only estimators, trained on hand-centric datasets, excel at detailed finger articulation but lack global body awareness. To address this, we propose Hand4Whole++, a modular framework that leverages the strengths of both pre-trained whole-body and hand pose estimators. We introduce CHAM (Conditional Hands Modulator), a lightweight module that modulates the whole-body feature stream using hand-specific features extracted from a pre-trained hand pose estimator. This modulation enables the whole-body model to predict wrist orientations that are both accurate and coherent with the upper-body kinematic structure, without retraining the full-body model. In parallel, we directly incorporate finger articulations and hand shapes predicted by the hand pose estimator, aligning them to the full-body mesh via differentiable rigid alignment. This design allows Hand4Whole++ to combine globally consistent body reasoning with fine-grained hand detail. Extensive experiments demonstrate that Hand4Whole++ substantially improves hand accuracy and enhances overall full-body pose quality.
Figures & tables
| Settings | Full-body datasets (Full/hands MPVPE) | Hand-only datasets (MPVPE/MRRPE) | ||||
|---|---|---|---|---|---|---|
| AGORA | ARCTIC | EHF | IH26M | ReIH | HIC | |
| Original whole-body [ 3 ] | 85.61/52.31 | 56.06/31.48 | 63.26/46.21 | 0 38.64/119.56 | 0 58.86/101.82 | 32.43/67.68 |
| Fine-tuned whole-body [ 3 ] | 90.77/55.91 | 67.52/29.03 | 126.34/57.35 | 20.00/47.89 | 24.87/28.32 | 32.30/62.11 |
| Hand-only [ 30 ] | 00 - 00 /99.11 | 00 - 00 /46.79 | 00 - 00 /46.28 | 000 11.17/94817.41 | 000 8.09/3094.65 | 0 15.44 /848.23 |
| Hand4Whole++ (Ours) | 76.84 / 49.71 | 45.95 / 25.03 | 61.24 / 33.43 | 0 9.40 / 32.30 | 0 7.98 / 16.37 | 17.72/ 29.09 |
| Wrist copy | CHAM | Full-body errors | Hands errors |
|---|---|---|---|
| (body root-relative) | (wrist-relative) | ||
| ✗ | ✗ | 84.76 | 52.31 |
| ✓ | ✗ | 90.70 | 100.59 |
| ✗ | ✓ | 76.88 | 50.56 |
| Finger | Shape | IH26M | ReIH | HIC |
|---|---|---|---|---|
| ✗ | ✗ | 14.69 | 18.13 | 21.68 |
| ✓ | ✗ | 12.26 | 15.24 | 19.61 |
| ✓ | ✓ | 9.40 | 7.98 | 17.72 |
| Methods | Full-body datasets (Full/hands MPVPE) | Hand-only datasets (MPVPE/MRRPE) | ||||
|---|---|---|---|---|---|---|
| AGORA | ARCTIC | EHF | IH26M | ReIH | HIC | |
| Hand4Whole [ 19 ] | 185.18/74.55 | 151.47/47.79 | 76.84/39.82 | 30.65*/219.26 | 0 71.57/310.69 | 0 22.73/101.72 |
| OSX [ 16 ] | 178.28/76.37 | 111.42/50.70 | 70.82/53.73 | 38.47*/173.56 | 0 71.10/221.83 | 35.51/94.57 |
| SMPLer-X [ 3 ] | 85.61/52.31 | 56.06/31.48 | 63.26/46.21 | 38.64*/119.56 | 0 58.86/101.82 | 32.43/67.68 |
| Hand4Whole++ (Ours) | 76.84 / 49.71 | 45.95 / 25.03 | 61.24 / 33.43 | 9.40 */ 32.30 | 0 7.98 / 16.37 | 17.72 / 29.09 |
| Methods | IH26M | ReIH | HIC |
|---|---|---|---|
| IntagHand [ 14 ] | 9.03 */48.04 | 19.31*/33.37 | 20.08*/52.46 |
| InterWild [ 25 ] | 10.28*/44.75 | 13.99/22.38 | 15.68/31.35 |
| HaMeR [ 29 ] | 0 9.53*/594.84 | 0 17.29/644.51 | 0 16.15/526.94 |
| WiLoR [ 30 ] | 00 11.17*/94817.41 | 000 8.09/3094.65 | 0 15.44 /848.23 |
| Hand4Whole++ (Ours) | 9.40*/ 32.30 | 0 7.98 / 16.37 | 17.72/ 29.09 |
| Settings | Point-to-point error (mm) |
|---|---|
| SMPL-X hands | 1.98 |
| MANO hands (Ours) | 1.34 |
| Settings | IH26M | ReIH | HIC |
|---|---|---|---|
| Without cross attention | 9.77/35.36 | 9.12/19.42 | 18.25/30.44 |
| With cross attention (Ours) | 9.40 / 32.30 | 7.98 / 16.37 | 17.72 / 29.09 |
| Hand detector | Hand pose estimator [ 30 ] | CHAM | Whole-body pose estimator [ 3 ] | Total |
| 0.01 | 0.05 | 0.01 | 0.03 | 0.1 |