titleG^3VLA: Geometric Inductive Bias for Vision-Language-Action Models
authorsYue Peng, Yongzhe Zhao, Artur Habuda, Khuyen Pham, Yanheng Zhu, Tran Nguyen Le, Fares Abu-Dakka, Li Guo
date2026-10-14
venuearXiv (preprint, not peer reviewed)
idarXiv:2606.24472
upvotes3 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
primerVision-language-action models
abstractVision-language-action (VLA) models have rapidly advanced generalist robot manipulation by harnessing the semantic knowledge of pretrained vision-language backbones. However, their visual representations are typically grounded in 2D image coordinates rather than calibrated camera geometry. This limitation is especially pronounced in multi-camera systems, where views are coupled by known intrinsics and extrinsics but processed as independent images. We propose G^3VLA, a camera-aware geometric module that injects calibrated structure into the visual-token stream of a pretrained VLA without altering its action space or original action-learning objective. G^3VLA combines intrinsic-conditioned ray embeddings, projective positional encoding (PRoPE), and bidirectional cross-view fusion to establish geometrically consistent representations across camera views. Geometric supervision is provided by ground-truth point maps or confidence-gated π^3X teacher predictions, enabling training without depth sensors or manual geometric annotations. On π_0, G^3VLA consistently improves performance on LIBERO and RoboCasa24 under both supervision regimes, while ground-truth supervision improves five-task RoboTwin2.0 averages with three cameras. Experiments on camera-shifted LIBERO-Goal and real robots demonstrate improved robustness to unseen camera viewpoints. Controlled calibration studies across π_0 and π_{0.5} show that these gains depend on correct camera geometry while remaining stable under mild calibration perturbations. These results demonstrate that grounding VLA visual tokens in calibrated camera geometry provides a simple and general mechanism for improving geometric consistency, multi-view reasoning, and viewpoint robustness in pretrained robot policies.

cite

@misc{peng2026g,
  title={G^3VLA: Geometric Inductive Bias for Vision-Language-Action Models},
  author={Yue Peng and Yongzhe Zhao and Artur Habuda and Khuyen Pham and Yanheng Zhu and Tran Nguyen Le and Fares Abu-Dakka and Li Guo},
  year={2026},
  eprint={2606.24472},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2606.24472}
}