UniMate: One Unified Model to Animate Diverse Skeletons
Organizations: Princeton University, USA · University of California, Berkeley, USA · Massachusetts Institute of Technology, USA · Nanyang Technological University, Singapore
Abstract
Recent advances in automatic rigging now deliver animation-ready 3D assets at scale, yet generating the motion to drive them remains a bottleneck. Existing learned animators are topology-constrained: they rely on category-specific templates or require per-skeleton fine-tuning and reference motions at inference. We present UniMate, a unified foundation model that synthesizes articulated motion for arbitrary skeletons from a rigged 3D asset and a text prompt, with no test-time optimization or per-skeleton retraining. UniMate introduces a topology-aware diffusion transformer, which integrates skeletal topology into attention via three mechanisms: (1) a graph-aware attention bias from pairwise joint relations and geodesic distances; (2) a spectral rotary position embedding generalizing RoPE to arbitrary kinematic trees via the graph Laplacian; and (3) a global topological conditioner attention-pooled from the rest-pose skeleton. We also curate UniML3D, 13,006 motion sequences spanning bipedal, quadrupedal, avian, marine, insectoid, serpentine, and articulated rigid objects with unified canonicalization and text pairing. Trained on this dataset, UniMate outperforms state-of-the-art baselines in quality, generalization, and efficiency, and supports zero-shot cross-topology transfer, in-betweening, expansion, and text-guided editing. Our project page is available at https://linzhanmou.com/unimate/.
Figures & tables
| Method | FID | Diversity |
|---|---|---|
| w/o graph-aware attention bias | 0.773 | 8.799 |
| w/o Spec-RoPE | 0.798 | 8.424 |
| w/o global topological conditioner | 0.825 | 9.475 |
| Full Model | 0.757 | 9.200 |
Appendix figures & tables10 assets
Supplementary material from the paper’s appendix.
Appendix
| Skeleton | Prompt | Skeleton | Prompt |
|---|---|---|---|
| Crab | A crab attacks forward. | Leapord | A leopard attacks forward. |
| A crab lunges forward to attack. | A leopard crouches low and bites forward. | ||
| A crab strikes forward with its claws. | A leopard collapses and lies on its side. | ||
| A crab snaps its claws and attacks. | A leopard falls backward and lies on its side. | ||
| A crab lowers its head and lies down. | A leopard crouches low. | ||
| A crab collapses backward and lies down. | A leopard growls with its head lowered. |
| Method | Skate | Slide |
|---|---|---|
| UniMate (Ours) | 0.107 | 0.542 |
| UniMate + FL | 0.023 | 0.191 |