ACTS: Learning Visuo-Tactile World Models from Human Physical Interaction
Authors: Yuxiang Ma, Weihan Xu, Pengfei Ye, Anna Mei, Yuxin Ray Song, Tingle Li, Haonan Chen, Edward H. Adelson
Organizations: Massachusetts Institute of Technology · University of Washington · Harvard University · University of California, Berkeley · Stanford University
Abstract Action-conditioned world models for contact-rich manipulation require data that captures how contact forms, slides, and releases under varying force. Such data are slow to collect through robot teleoperation, which often lacks force feedback and is constrained by gripper geometry. We ask whether these dynamics can instead be learned from human physical interaction and transferred to a robot. We present ACTS, a visuo-tactile world model trained only on human interaction data. Operators manipulate handheld GelSight sensors while we record third-person and wrist video, tactile images, 6-DoF sensor motion, and tactile-derived normal force, yielding React, a 4.9-hour bimanual dataset across three objects. We represent actions at the tactile sensor as motion augmented by force change, providing a shared action space for human collection and robot execution. ACTS jointly predicts future scene, wrist, and tactile observations. On held-out human data, ACTS improves scene-view prediction by 0.7-2.0 dB PSNR over the stronger of two visuo-tactile world models trained from scratch on React. Without fine-tuning, in the robot teleoperation rollouts we inspected, predicted tactile imprints still appear and disappear with recorded contact. Visual transfer is less robust: camera predictions exceed frame copying on PushT, are mixed on Rope, and fall below it on Motherboard, while wrist views can blur or hallucinate structure. These results suggest that contact dynamics transfer more reliably than visual appearance from human to robot.
Figures & tables
Figure 1: Force-informed sensor actions. (a) Top: scene view, with the sensor of (b) boxed. Estimated normal force f shifts the sensor target by kffns along the gel normal, so each action includes kfΔfns (Eq. 3 ). (b) On a held-out PushT sequence, the force-conditioned model forms the tactile imprint at contact, while the pose-only model does not. Tactile crops are shown at 2 × contrast.
Figure 2: Overview of ACTS. Frozen encoders produce observation latents, whose spatial patches are mapped to tokens by input projectors Pin . A generator initialized from pretrained Cosmos3 weights jointly processes noisy future tokens conditioned on clean history, force-aware sensor actions, and view-aligned actions. Output projectors Pout map target-token features to latent velocity predictions. The scene and two wrist streams share the RGB projector pair (PVin,PVout) , while both tactile streams share (PTin,PTout) . Sampling updates only future latents, which frozen decoders reconstruct into synchronized multimodal predictions.
Figure 3: Qualitative results on a held-out PushT window. Given eight observed frames (left) and the recorded sensor actions, ACTS predicts the next eight frames of the scene view, both wrist views, and both GelSight streams. Ground truth in blue boxes, predictions in orange boxes. Videos and results on all tasks: https://acts-anon.github.io/ .
Video
Wrist (L)
Wrist (R)
Tactile (L)
Tactile (R)
Task
Metric
Copy
Ours
Copy
Ours
Copy
Ours
Copy
Ours
Copy
Ours
Rope
PSNR ↑
25.10
28.92
17.66
22.30
19.66
23.70
44.74
46.08
46.46
46.51
SSIM ↑
0.848
0.907
0.657
0.769
0.704
0.796
0.986
0.988
0.990
0.990
LPIPS ↓
0.115
0.045
0.261
0.131
0.234
0.129
0.033
0.021
0.027
0.020
PushT
PSNR ↑
25.21
29.69
19.32
22.86
19.20
22.76
46.24
46.42
48.73
48.37
SSIM ↑
0.861
0.925
0.762
0.834
0.766
0.844
0.986
0.988
0.991
0.991
Table 1: Short-horizon prediction quality over 8 frames ( 0.53 s). Copy repeats the last observed frame across the prediction window. ACTS consistently improves the camera streams, while high temporal persistence makes full-frame tactile metrics less discriminative.
Task
Model
PSNR ↑
SSIM ↑
LPIPS ↓
Rope
ContactWorld ( 2026 )
26.03
0.846
0.164
VT-WM-style ( 2026 )
28.05
0.8878
0.1118
Ours
28.92
0.907
0.045
PushT
ContactWorld ( 2026 )
26.35
0.858
0.139
VT-WM-style ( 2026 )
27.69
0.8916
0.1047
Ours
29.69
0.925
0.038
Table 2: Scene-view prediction on held-out human data over 8 frames ( 0.53 s). Both baselines are trained from scratch on React. Best results per object are shown in bold.
Video
Wrist (L)
Wrist (R)
Tactile (L)
Tactile (R)
Task
Metric
Copy
Ours
Copy
Ours
Copy
Ours
Copy
Ours
Copy
Ours
Rope
PSNR ↑
31.57
32.31
27.29
27.88
27.70
27.28
42.74
42.56
44.73
44.65
SSIM ↑
0.944
0.942
0.827
0.845
0.838
0.856
0.980
0.980
0.986
0.986
LPIPS ↓
0.021
0.022
0.055
0.055
0.054
0.057
0.043
0.029
0.040
0.025
PushT
PSNR ↑
27.75
29.85
25.84
26.71
23.96
25.62
45.66
44.15
45.49
44.25
SSIM ↑
0.915
0.924
0.850
0.863
0.827
0.853
0.980
0.982
0.984
0.984
Table 3: Zero-shot short-horizon prediction on robot teleoperation (8 frames, 0.53 s), scored against VAE-reconstructed ground truth. Copy repeats the last observed frame; slow robot motion makes it a strong baseline.
Appendix figures & tables6 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 4: Human data collection setup. Left: the workspace and three fixed cameras. Top right: the two handheld devices and their sensing hardware. Bottom: the motherboard, PushT block, and rope used for collection.
Object
Recordings
Segments
Duration (min)
Motherboard
12
25
93.9
PushT
30
92
96.4
Rope
18
70
104.1
Total
60
187
294.4
Appendix
Table 4: Dataset statistics after curation. Duration is computed from the number of aligned time steps at 30 Hz and counts each bimanual interaction once.
Figure 5: Zero-shot rollout on robot teleoperation. A held-out robot PushT window in which the sensor breaks contact with the block, predicted without fine-tuning by the model trained on human data. Given eight observed frames (left) and the robot’s sensor actions, ACTS predicts the next eight frames of the scene view, both wrist views, and both GelSight streams. Ground truth in blue boxes, predictions in orange boxes. The scene and left tactile predictions follow the recording as the sensor lifts off. In the left wrist view, the recorded frames barely change, while the predicted block face grows and shifts from t+4 onward. More robot rollouts: https://acts-anon.github.io/ .
Task
Episodes
Windows
Steps/epoch
Train
Val
Test
Train
Val
Test
PushT
56
4
8
55,199
4,439
5,756
6,900
Rope
53
8
9
77,188
6,363
8,468
9,648
Motherboard
21
2
5
71,386
5,411
16,699
8,923
Appendix
Table 5: Dataset splits and training sizes. Splits are defined by complete source episodes. Window counts correspond to examples used for training and evaluation.
Figure 6: Effect of the force term on tactile prediction. A held-out PushT window in which the right sensor touches the block. Rows: ground truth (blue), force-informed actions (orange), pose-only actions (gray) for the right wrist and GelSight streams; numbers are per-frame PSNR. Bottom: recorded normal force (black, left axis) and per-step action along the gel normal ns (Eq. 3 ; right axis, broken), pose-only (gray) and force-informed (orange), with the force increment kfΔf above each orange bar; the dotted line marks contact. The force term adds 1.2 mm over the window, and only the model that receives it forms the imprint.
Task
Force
Stream
PSNR ↑
SSIM ↑
LPIPS ↓
Rope
–
Video
28.50
0.9021
0.0495
Wrist (L)
21.68
0.7583
0.1444
Wrist (R)
23.62
0.7966
0.1353
Tactile (L)
45.90
0.9874
0.0230
Tactile (R)
46.30
0.9898
0.0188
✓
Video
28.56
0.9028
0.0490
Appendix
Table 6: Ablation of force information in action conditioning. All observation streams are retained. A checkmark indicates that force information is included in the action representation. Within each dataset, bold values indicate a significant difference between the force and no-force configurations for the same observation stream (paired t -test, p<0.05 ). All configurations are evaluated after 10 training epochs for a fair comparison.
Peking University Beijing, China · Nanjing University Nanjing, China · State Key Laboratory of Multimedia Information Processing, School of Computer Science, Peking University Beijing, China