titleRigidFormer: Learning Rigid Dynamics using Transformers
authorsZhiyang Dou, Minghao Guo, Haixu Wu, Doug Roble, Tuur Stuyck, Wojciech Matusik
date2026-05-09
venuearXiv (preprint, not peer reviewed)
idarXiv:2605.09196
affiliationMassachusetts Institute of Technology
upvotes13 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf code
abstractLearning-based simulation of multi-object rigid-body dynamics remains difficult because contact is discontinuous and errors compound over long horizons. Most existing methods remain tied to mesh connectivity and vertex-level message passing, which limits their applicability to mesh-free inputs such as point clouds and leads to high computational cost. Efficiently modeling high-fidelity rigid-body dynamics from mesh-free representations, therefore, remains challenging. We introduce RigidFormer, an object-centric Transformer-based model that learns mesh-free rigid-body dynamics with controllable integration step sizes. RigidFormer reasons at the object level and advances each object through compact anchors; Anchor-Vertex Pooling enriches these anchors with local vertex features, retaining contact-relevant geometry without dense vertex-level interaction. We propose Anchor-based RoPE to inject anchor geometry into attention while respecting the unordered nature of objects and anchors: object-token processing is permutation-equivariant, and the mean-pooled anchor descriptor is invariant to anchor reindexing while preserving shape extent. RigidFormer further enforces rigidity by projecting updates onto the rigid-body manifold using differentiable Kabsch alignment. On standard benchmarks, RigidFormer outperforms or matches mesh-based baselines using point inputs, runs faster, generalizes to unseen point resolutions and across datasets, and scales to 200+ objects; we also show a preliminary extension to command-conditioned articulated bodies by treating body parts as interacting object-level components.

cite

@misc{dou2026rigidformer,
  title={RigidFormer: Learning Rigid Dynamics using Transformers},
  author={Zhiyang Dou and Minghao Guo and Haixu Wu and Doug Roble and Tuur Stuyck and Wojciech Matusik},
  year={2026},
  eprint={2605.09196},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2605.09196}
}