3PoinTr: 3D Point Tracks for Learning Manipulation from Unconstrained Human Videos
About
Learning manipulation policies from human videos could greatly reduce the need for expensive robot demonstrations, but existing approaches typically require restrictive assumptions such as choreographed human motions, predefined keypoints, manual annotations, or known grasp locations. We propose 3PoinTr, a method for pretraining sample-efficient robot policies from unconstrained human videos by predicting dense 3D point tracks. In the unconstrained human demonstration videos, humans are free to follow whatever trajectories and manipulation strategies they see fit, rather than choreographing their motions to mimic a robot. 3PoinTr uses a lightweight visibility-aware transformer to learn how scene points should move from human videos, and then trains a closed-loop multitask robot policy to flexibly extract action-relevant priors from those predicted point tracks. With only 20 action-labeled robot demonstrations, 3PoinTr achieves a 25.0 percentage point higher average success rate than the strongest behavior cloning and video-pretraining baselines on real-world tasks, and a 29.6 percentage point higher average success rate in simulation. Targeted ablations support the key design choices and confirm the benefit of learning from actionless videos. We further show that 3PoinTr's point track prediction transformer outperforms a strong baseline by preserving supervision over partially occluded points. Project page: https://adamhung60.github.io/3PoinTr/.