Perceive, Predict, and Plan: a Unified World Action Model for Egocentric Dexterous Manipulation
Authors: Zirui Wu, Chen Guo, Tianjian Jiang, Zeren Jiang, Zeming Li, Lingchen Yang, Longteng Duan, Ying Xue, Handi Yin, Shenyuan Gao, Martin R. Oswald, Jun Zhang, Ping Tan, Jie Song
Organizations: HKUST (GZ) · Primatix · ETH Zurich · Visual Geometry Group, University of Oxford · HKUST · University of St. Gallen
We introduce P3-WAM, a unified world action model for egocentric dexterous manipulation that learns 3D perception, action-conditioned prediction, and goal-directed planning through three complementary modes: Perceive, which reconstructs articulated hand motion and camera trajectories from video; Predict, which generates visual futures under prescribed actions; and Plan, which jointly generates action trajectories and their anticipated visual consequences conditioned on an initial image, a language instruction, and an optional visual goal. Our model integrates a compact, structured 3D action representation into a pretrained video diffusion transformer through a mixture-of-transformers architecture with shared base weights, modality-specific adaptation, and bidirectional visual-action attention. Randomized modality visibility lets video and 3D actions serve as either conditioning context or prediction targets across the three modes. Experiments show that unified training improves all three capabilities over single-mode training, including gains in planning quality under a vision-language model evaluation. Through unified training, our model outperforms specialized baselines on 3D hand reconstruction and action-conditioned video prediction across four datasets, while producing goal-directed manipulation videos with stronger instruction adherence and action progression than video-generation baselines. Project Page: https://p3-wam.pages.dev/
Figures & tables
Figure 1: P 3 -WAM unifies perception, prediction, and planning. Perceive recovers hand motion from video; Predict generates video under prescribed motion; Plan jointly generates motion and video guided by text instructions and optional visual goals.
Figure 2: Task modes and unified training. Colored tiles denote observed video V and actions A ; gray tiles denote missing inputs. Unified training samples these patterns across clips and time.
Figure 3: P 3 -WAM couples video and action streams through joint attention and shared base weights. The action expert adds low-rank adaptation and directly predicts hand and camera states.
Figure 4: Visual goals specify spatial targets. (a) A goal image specifies how far apart the red blocks should be. (b) Intermediate goal images guide the block arrangement at each stage of a longer task; without them, placement errors accumulate.
Perceive (mm)
Predict (full frame)
Dataset
Training setting
MPJPE ↓
RR-MPJPE ↓
PA-MPJPE ↓
PSNR ↑
SSIM ↑
LPIPS ↓
FVD ↓
EgoDex-MANO
Single mode
52.491
29.170
12.577
23.106
0.8178
0.3090
757.06
Unified training
47.587
25.637
12.184
23.668
0.8182
0.3096
653.49
ARCTIC
Single mode
227.608
27.335
13.144
12.431
0.5501
0.4940
1144.02
Unified training
150.501
22.946
12.154
13.431
0.5687
0.4661
1035.38
HOT3D
Single mode
80.656
31.318
12.317
14.917
0.4151
0.5189
1466.68
Table 1: Unified versus single-mode training on Perceive and Predict .
Dataset
Method
MPJPE- p ↓
RR-MPJPE- p ↓
PA-MPJPE- p ↓
F1 ↑
EgoDex-MANO
Ours
32.92
31.58
13.12
99.96
HaMeR
112.92
44.35
16.22
91.48
Dyn-HaMR
115.53
36.66
18.29
98.17
ARCTIC
Ours
45.29
13.08
7.64
99.72
HaMeR
85.34
28.87
11.51
97.31
Dyn-HaMR
317.46
48.28
39.40
89.88
Table 3: Presence-aware Perceive reconstruction, measured by camera-space, root-relative (RR), and Procrustes-aligned (PA) MPJPE- p in mm ( ↓ ), and hand-visibility F1 in percent ( ↑ ).
Figure 5: Qualitative Perceive comparisons across EgoDex, ARCTIC, HOT3D, and EgoLive. Red boxes highlight missed hands or local pose errors in baseline predictions.
Figure 6: Qualitative Predict comparisons on EgoDex, HOT3D, ARCTIC, and EgoLive.
Full frame
Hand region
Dataset
Method
PSNR ↑
SSIM ↑
LPIPS ↓
CLIP-I ↑
FVD ↓
PSNR ↑
SSIM ↑
LPIPS ↓
CLIP-I ↑
IoU ↑
EgoDex
Ours
24.511
0.8462
0.2679
0.9448
401.26
21.498
0.7265
0.3362
0.9203
0.7082
Wan2.2-Fun-Control
20.304
0.7570
0.3682
0.9254
719.66
18.016
0.6342
0.4488
0.8923
0.6306
DreamDojo
19.561
0.7583
0.3781
0.8868
931.96
17.498
0.6285
0.4842
0.8537
0.3005
Hand2World
13.287
0.6639
0.6656
0.7894
3028.61
12.290
0.5506
0.6580
0.8011
0.5296
EgoSim
21.331
0.8189
0.2955
0.9242
649.87
19.447
0.6982
0.3647
0.9078
0.6474
Table 4: Action-conditioned video prediction across four datasets. CLIP-I measures image-feature similarity and IoU measures hand-box overlap. Darker greens mark the top three results.
Method
Goal image
Action process
Instruction adherence
Physical interaction
Temporal / identity consistency
Goal transition
Cosmos 3-Nano
✓
2.279
2.703
3.190
2.852
2.080
Cosmos 3-Nano
✗
2.725
2.817
4.146
4.684
2.732
Wan2.2 I2V-A14B
✓
2.647
2.847
3.251
2.741
2.273
Wan2.2 I2V-A14B
✗
3.120
3.119
4.119
4.406
3.178
Ours
✓
3.591
3.739
4.350
4.651
3.841
Δ
–
+0.471
+0.620
+0.205
−0.033
+0.663
Table 5: VLM comparison of Plan -generated videos with video-generation baselines. Δ compares Ours with the best baseline score for each metric across the four baseline settings.
Figure 7: Goal-conditioned Plan comparisons.
Figure 8: Robot deployment. Each example shows the initial observation, generated human motion, and robot execution after retargeting.
Appendix figures & tables15 assets
Supplementary material from the paper’s appendix.
Appendix
Evaluation
Cam. (mm)
World (mm)
RR (mm)
UV (px)
Depth (mm)
EgoDex
0.868
1.048
0.967
0.323
0.432
ARCTIC
2.600
4.212
2.543
0.882
1.137
HOT3D
1.336
2.088
1.406
0.580
0.691
EgoLive
1.498
1.627
1.573
0.470
0.891
Appendix
Table 6: Multi-domain action-codec reconstruction quality on held-out validation data. All values are dataset means; lower is better.
Figure 9: Plan conditioning masks and goal encoding. Both settings observe the initial image; the default also fixes a terminal latent encoded from repeated copies of the goal image. Hand and camera trajectories are predicted for all frames.
Human
VLM
Dimension
Plan -only
Unified training
Gain [95% CI]
Plan -only
Unified training
Gain [95% CI]
Action process
2.23
3.12
+0.88 [0.37, 1.42]
1.88
2.89
+1.01 [0.73, 1.33]
Instruction adherence
2.18
3.02
+0.83 [0.43, 1.23]
2.27
3.22
+0.94 [0.62, 1.28]
Physical interaction
1.98
2.90
+0.92 [0.53, 1.33]
2.52
3.32
+0.80 [0.46, 1.13]
Temporal / identity
2.05
3.30
+1.25 [0.73, 1.77]
2.15
3.57
+1.42 [1.08, 1.76]
Goal transition
1.72
3.55
+1.83 [1.33, 2.30]
1.98
3.29
+1.30 [1.03, 1.60]
Appendix
Table 7: Human and VLM evaluation of Plan -only and unified training. Human scores use 21 pairs across 15 tasks; VLM scores use 188 pairs across 17 tasks. Scores range from 1 to 5. Unified training gains include 95% bootstrap confidence intervals.
Dimension
1: Severe failure
3: Partial completion
5: Good visible performance
Action process (primary)
No effective action, wrong direction, or arrival through a sudden jump.
Some necessary actions are visible, but key steps are missing or transitions are flawed.
Necessary actions occur clearly in a plausible order; intermediate states support the outcome.
Instruction adherence (primary)
Core instruction is not executed, or the stopping condition is seriously violated.
Some instructions are executed, with visible omissions or constraint violations.
Observable requirements and constraints are met, with the correct stopping point.
Physical interaction
Severe penetration, self-moving or disappearing objects, or invalid interaction.
Clear local problems in contact or shape.
Observed contact, grasping, movement, and shape changes are plausible.
Temporal / identity consistency
Severe jumps or changes in object count or identity.
Local discontinuities or shape drift.
Observed hands, objects, and background remain consistent across frames.
Goal transition
No approach to the goal, or sudden replacement at the end.
Partly natural approach, with clear late corrections or discontinuities.
Natural transition across the final frames, with the required relationships established.
Appendix
Table 8: Shared human/VLM score anchors. Unobservable dimensions are recorded as missing.
Baseline
Goal image
Action process
Instruction adherence
Cosmos 3-Nano
✓
1.311[1.190,1.439]
1.036[0.874,1.189]
Cosmos 3-Nano
✗
0.865[0.661,1.060]
0.922[0.657,1.178]
Wan2.2 I2V-A14B
✓
0.944[0.743,1.143]
0.892[0.669,1.107]
Wan2.2 I2V-A14B
✗
0.471[0.245,0.703]
0.620[0.364,0.875]
Appendix
Table 9: Ours-minus-baseline VLM score differences with 95% bootstrap intervals. Positive differences indicate higher scores for Ours.
Figure 10: Interface of the questionnaire. Reviewers see the instruction, initial and goal images, and one anonymous video.
Figure 11: Questionnaire response interface. Each dimension has a 1–5 rating and an unobservable option, with optional notes.
Joint error (mm)
Hand visibility (%)
Dataset
Method
MPJPE ↓
RR-MPJPE ↓
PA-MPJPE ↓
Precision ↑
Recall ↑
F1 ↑
EgoDex-MANO
Ours
32.92
31.58
13.12
99.92
100.00
99.96
HaMeR
106.86
43.49
14.80
84.98
99.06
91.48
Dyn-HaMR
103.58
33.82
15.05
99.52
96.86
98.17
ARCTIC
Ours
42.31
13.03
7.57
99.93
99.51
99.72
HaMeR
51.36
27.36
9.42
99.23
95.47
97.31
Appendix
Table 10: Joint reconstruction and hand visibility in Perceive mode. We report camera-space, root-relative (RR), and Procrustes-aligned (PA) joint errors without missing-hand penalties, alongside separately scored hand-in-frame precision, recall, and F1.
Without presence penalties
With presence penalties
Method
MPJPE
RR-MPJPE
PA-MPJPE
MPJPE- p
RR-MPJPE- p
PA-MPJPE- p
HaMeR
106.23
39.75
11.98
112.30
40.90
13.70
Dyn-HaMR
102.62
24.20
12.26
114.58
27.45
15.86
Ours
30.07
19.02
10.98
30.07
19.02
10.98
Appendix
Table 11: Reconstruction against original EgoDex joint annotations. Errors are in mm (lower is better); p denotes presence penalties.
Frames 2 – 81
Frames 2 – 77
Image source
MPJPE
RR-MPJPE
MPJPE
RR-MPJPE
EgoDex
4.79
2.31
4.78
2.32
Generated images
4.99
2.76
4.96
2.79
Appendix
Table 12: Agreement between Plan hand trajectories and Perceive reconstructions of the generated videos. MPJPE is in mm (lower is better).
Scale γ
Full-image PSNR ↑
SAM3 20% hand PSNR ↑
0.0
20.644
16.764
0.5
23.726
21.008
1.0
25.327
23.724
1.5
25.271
23.899
2.0
25.035
23.651
Appendix
Table 13: Action-guidance sensitivity for Predict on 20 EgoDex windows. Full-image PSNR is measured on native 848×480 frames 2–81. Hand PSNR is measured inside 128×128 GT-pose crops using GT-only SAM3 hand pixels with at least 20% crop coverage. Higher is better.
Dataset
Method
PSNR ↑
SSIM ↑
LPIPS ↓
EgoDex
Ours (Wan2.2)
24.511
0.8462
0.2679
Ours (Wan2.1)
23.540
0.8262
0.2984
EgoSim
21.331
0.8189
0.2955
ARCTIC
Ours (Wan2.2)
14.106
0.5785
0.4411
Ours (Wan2.1)
13.921
0.5903
0.4437
EgoSim
12.874
0.5545
0.4968
Appendix
Table 14: Predict results with Wan2.2 and Wan2.1 backbones, alongside EgoSim. Full-frame metrics follow Table 4 . Macro averages the four datasets equally. Bold entries denote the best result for each dataset.
Dataset
Method
MPJPE ↓
RR-MPJPE ↓
PA-MPJPE ↓
EgoDex
Ours (Wan2.2)
32.92
31.58
13.12
Ours (Wan2.1)
30.31
18.79
10.88
ARCTIC
Ours (Wan2.2)
42.47
12.99
7.55
Ours (Wan2.1)
38.99
13.14
8.36
HOT3D
Ours (Wan2.2)
87.07
20.12
9.42
Ours (Wan2.1)
109.99
24.86
10.05
Appendix
Table 15: Perceive results with Wan2.2 and Wan2.1 backbones. We report ordinary camera-space, root-relative (RR), and Procrustes-aligned (PA) MANO joint errors in millimeters. Wan2.2 entries evaluate the dense predictions from Table 3 before visibility filtering and mesh matching. Macro averages the four datasets equally.
Figure 12: Qualitative comparison of single-mode and unified training. Perceive : unified training places the reconstructed palm closer to the observed hand. Predict : the table extent and viewpoint more closely match GT. Plan : the narrow support is positioned beside the fixed broad post. The left column shows GT for Perceive and Predict , and the goal-image reference for Plan .
Figure 13: Plan and video-generation baselines without a goal image. All methods receive only the initial image and instruction. Our model maintains the support’s shape during placement and the identities of the puzzle pieces during separation. The close-ups show deformations in the baseline outputs.