Despite recent progress in dexterous reference tracking, existing models focus primarily on single-hand manipulation and a limited range of interactions, leaving the bimanual dexterous behaviors common in real life unaddressed. The scarcity of contact-rich bimanual manipulation data and the increased complexity of coordinating contacts make developing a generalist bimanual tracker particularly challenging. Therefore, we present 1) DONIC, the first generalist bimanual tracker jointly trained across operation categories and human-motion sources, together with 2) BiHOI, a multi-view dataset of 1,575 sequences spanning 229 objects and emphasizing sustained bimanual interaction, where reconstructed interactions are retargeted into robot references. DONIC combines proximal policy optimization with behavioral cloning in a feedback loop that recycles verified successful executions into training demonstrations. An object-centered per-hand reward maintains object-motion feedback while supervising each hand according to its reference contact role. Clip-Centered Advantages remove reference-dependent advantage offsets while preserving within-trajectory differences. Together, these designs enable one single policy to learn coordinated manipulation across heterogeneous references. Without finetuning, a single checkpoint achieves 86.79% success on unseen trajectories of training objects and 57.32% on held-out objects, surpassing the state-of-the-art bimanual tracking baselines by 77.36 and 45.73 percentage points.
Figures & tables
Source
Capture
Sequences
Frames
Objects
Bimanual contact (%)
BiHOI (ours)
MV RGB
1,575
≈ 1.60M †
229
65.91
GRAB [ 2020 ]
Marker MoCap
1,334
1.622M
51
32.21
OakInk2 [ 2024 ]
MV RGB + MoCap
627
4.01M
75
24.97
TACO (V1) [ 2024 ]
MV RGB + ego RGB-D
2.5K
5.2M
206
15.69
GigaHands [ 2025 ]
MV RGB
–
183M
417
34.74
H2O [ 2021 ]
MV RGB-D
–
571.6K
8
38.57
Table 1: Dataset overview: source statistics and simultaneous-contact rates on analyzed recordings.
Figure 2: Overview of DONIC . Top: BiHOI captures are reconstructed and retargeted, then combined with public-data references to form the training pool. Middle: A shared bimanual policy learns through simulated interaction and verified demonstrations in an iterative PPO+BC loop. Bottom: An object-centered per-hand reward, Clip-Centered Advantages (CCA), and behavioral cloning provide complementary learning signals.
Figure 3: Qualitative comparisons on two held-out object trajectories. Rows show the reference, Dexplore-bi, DexTrack-bi, and DONIC ; time runs left to right.
Dataset
Method
To↓
Ro↓
Th↓
Rh↓
Efinger↓
SR ↑
Comp ↑
(cm)
(rad)
(cm)
(rad)
(rad)
(%)
(%)
Unseen trajectory
DexTrack-bi
41.86
2.3340
23.03
0.8296
0.6301
0.00
1.30
Dexplore-bi
14.73
0.8597
21.88
0.8412
0.3166
9.43
27.87
w/o CCA
11.27
0.9585
4.34
0.2980
0.0433
81.13
62.72
w/o contact gate
10.26
0.9589
4.00
0.3013
0.0338
81.13
65.03
Ours
10.27
0.9277
3.96
0.2905
0.0372
86.79
67.62
Table 2: Reference tracking without fine-tuning, using one checkpoint per method across both splits. Black and blue bold mark the best and second-best results within each split; ties share highlighting.
Appendix figures & tables5 assets
Supplementary material from the paper’s appendix.
Appendix
Source
Training sequences
Simultaneous contact (%)
GRAB
505
32.21
GigaHands
592
34.74
OakInk2
449
24.97
H2O
127
38.57
TACO
172
15.69
Public-data pool
1,845
—
Appendix
Table S1: Training inventory and simultaneous bimanual contact. Contact proportions pool frames across analyzed recordings, dividing both-hand-contact frames by frames with at least one hand in contact. The public-only model uses the public subsets listed below; Ours+BiHOI adds all BiHOI sequences.
Figure S1: Reconstruction and annotation pipeline. Synchronized multi-view RGB observations are processed to obtain SAM3 object masks and metric depth maps. The object branch performs metric reconstruction followed by robust multi-view 6D tracking, while the hand branch performs participant-specific hand calibration and multi-view hand-pose reconstruction. The two branches are finally refined jointly using depth-guided hand–object optimization.
Parameter
Setting
(βhand,βobj,βcont,βhold)
(0.25,0.45,0.15,0.15)
(κp,κR,κv)
(9,2,14)
(fmin,δmax)
(0.5N,0.03m)
(κc,ζ)
(30m−1,0.5)
Parallel simulation environments
8,192
BC coefficient / pairs per minibatch
50 / 4,096
Appendix
Table S2: Reward and generalist-training settings. Distances in reward exponents use metres, rotations radians, and velocities metres per second.
Setting
Value
Optimizer / learning rate / schedule
Adam / 2×10−5 / constant
Rollout horizon / PPO minibatch
64 / 16,384
PPO passes per rollout / clipping radius
6 / 0.2
Discount / GAE trace parameter
0.99 / 0.95
Value / entropy / action-bound loss coefficients
5 / 0 / 10
Value clipping / gradient truncation
Disabled / disabled
Appendix
Table S3: Optimization and simulation configuration.
Figure S2: Qualitative bimanual tracking comparisons. Rows in each group show the reference, Dexplore-bi, DexTrack-bi, and DONIC (Ours); time runs left to right.