Reward design remains a major bottleneck for reinforcement learning in robotic manipulation. Handcrafted dense rewards can compensate for the limited guidance provided by sparse rewards, but require substantial task-specific reward engineering. Learning rewards from videos provides a scalable, data-driven alternative to manual reward design. However, existing video-based rewards are often computed in entangled visual spaces where task-relevant state changes are confounded with extraneous visual variation. As a result, the learned reward may respond to visual distractors instead of actual task execution. To address this limitation, we propose DiTaR (Disentangling Task-Relevant Latent Dynamics for Reward Modeling), a framework for learning dense rewards from heterogeneous videos. DiTaR learns a continuous task-relevant representation from multi-frame video latents through an asymmetric two-stage procedure that suppresses task-irrelevant visual variation. In the task-relevant latent space, we train a history- and language-conditioned rectified-flow model to capture task dynamics and derive a directional dense reward from temporal changes in dynamics compatibility. Together, these components enable reward modeling directly over task-relevant dynamics rather than generic visual variation. DiTaR substantially improves policy learning on MetaWorld-v3 and ManiSkill over video-based reward baselines, and transfers to real-world offline RL through reward relabeling. Reward analyses further show that DiTaR provides more reliable rewards.
Figures & tables
Figure 1: DiTaR learns dense rewards from task-relevant latent dynamics. The DiTaR reward accelerates RL convergence while remaining stable under nuisance visual variations, enabling robust policy learning across diverse tasks.
Figure 2: Pipeline overview. DiTaR disentangles task-irrelevant and task-relevant latents through an asymmetric two-stage representation learning procedure. A history- and language-conditioned rectified-flow model captures task-relevant transition dynamics, and the temporal difference of its residual-based compatibility score provides the dense reward.
Benchmark
Method
Final SR ↑
SR ≥ 80 ↑
Reach 0.8 ↑
NormT @ 0.8 ↓
MetaWorld
Env-only
56.8
50.0
50.0
0.68
VIPER
39.9
33.3
41.7
0.73
Diff. Reward
13.1
8.3
8.3
0.92
ReWiND
65.2
33.3
41.7
0.61
DiTaR
94.3
91.7
91.7
0.24
ManiSkill
Env-only
74.6
50.0
75.0
0.58
Table 1: Aggregate RL performance on MetaWorld and ManiSkill. We report final success rate, task coverage, and normalized time-to-threshold. ↑ higher is better, ↓ lower is better.
Figure 3: Main RL performance. DiTaR achieves strong and consistent policy learning across 12 MetaWorld and 4 ManiSkill tasks, outperforming Env-only, VIPER, Diffusion Reward, and ReWiND in aggregate performance. Panels use task-specific x-axis ranges for readability.
Figure 4: Ablation on history conditioning. Removing visual history from the conditional dynamics model reduces learning efficiency and final performance across the evaluated MetaWorld tasks.
Figure 5: Ablation on temporal-difference reward. Temporal differencing improves policy learning over directly using the absolute compatibility score ϕt across MetaWorld and ManiSkill tasks.
MetaWorld
Real-world
Perturbation
DiTaR
Diff. R.
VIPER
ReWiND
DiTaR
Diff. R.
VIPER
ReWiND
(a) Temporal sensitivity: Δ (%) ↓
Locally shuffled
−22.2
−0.6
−10.2
+0.1
−3.2
+0.1
−10.0
+0.2
Temporal jitter ±2
−19.1
−0.3
−4.7
+1.5
−4.2
−0.2
−5.5
+0.6
Shuffled chunks
−28.9
+0.5
−9.3
−15.9
−7.0
−1.6
−11.8
+19.1
(b) Visual robustness: ∣Δ∣ (%) ↓
Table 2: Reward sensitivity and robustness. For temporal perturbations, Δ denotes the signed reward change from clean trajectories, with more negative values indicating stronger temporal sensitivity. For visual perturbations, ∣Δ∣ denotes the reward-change magnitude, with smaller values indicating greater robustness. Diff. R.: Diffusion Reward.
Figure 6: Reward robustness to visual perturbations. Per-frame reward trajectories on MetaWorld expert rollouts under lighting changes and 1.25× camera zoom. Δ denotes the relative mean reward change from the clean rollout. DiTaR shows substantially smaller reward shifts than VIPER, Diffusion Reward, and ReWiND under both perturbations.
Figure 7: Real-world task suite. Three tabletop manipulation tasks used for offline RL evaluation: (a) object-to-basket placement, (b) bottle-to-plate placement, and (c) knife-to-glove placement.
Metric
VIPER
Diffusion Reward
ReWiND
DiTaR
Success Rate
16.7%
26.7%
43.3%
83.3%
Table 3: Real-world offline RL results. All methods relabel the same offline demonstrations and use the same IQL training pipeline. We conduct 10 evaluation trials per task.
Appendix figures & tables16 assets
Supplementary material from the paper’s appendix.
Appendix
Dataset
Ratio (%)
View
Frame stride
AgiBotWorld ( Bu et al., 2025a )
38.0
Head
{1,2,3,4}
DROID ( Khazatsky et al., 2024 )
38.0
Exterior
{1,2,3,4}
Bridge ( Walke et al., 2023 )
19.0
Exterior
{1,2,3}
MetaWorld ( McLean et al., 2025 )
2.5
Left
{1,2}
ManiSkill ( Gu et al., 2023 )
2.5
Default
1
Appendix
Table 4: Video sources, proportions, camera views, and frame strides used for DiTaR pretraining.
Bridge
Real-world
Corruption
DiTaR
Diff. R.
VIPER
DiTaR
Diff. R.
VIPER
Signed reward change: Δ (%) ↓
Backward drift
−2.4
−1.1
−0.5
−1.6
+7.0
+0.6
Looped segment
−3.5
−0.6
−1.7
−1.0
+7.4
+0.7
Shuffled chunks
−16.8
−0.7
−6.0
−9.2
−2.5
−11.8
Duplicate frames
−21.1
+0.9
+7.0
−26.4
+6.8
+5.3
Appendix
Table 5: Temporal sensitivity. Signed reward changes Δ (%) over 16 expert episodes per dataset. More negative values indicate stronger temporal sensitivity. The largest decrease per row and dataset is bold. Diff. R.: Diffusion Reward.
Figure 8: Temporal corruption on Bridge. Clean and corrupted rewards over 16 episodes. Bands indicate one standard deviation; Δ is the mean signed reward shift.
Figure 9: Temporal corruption localization. Temporal jitter of ±2 frames is applied to the shaded middle third. Left two columns: MetaWorld, “take the object out of the hole.” Right: ManiSkill, “push the red T-shaped block into place.” Solid and dashed curves show clean and corrupted rewards.
Dataset
Method
Temporal jitter ↑
Local shuffling ↑
MetaWorld
VIPER
0.91
0.96
MetaWorld
DiTaR
0.95
1.00
ManiSkill
DiTaR
0.83
0.94
Appendix
Table 6: Temporal corruption localization. Mean localization AUCs on MetaWorld and ManiSkill; higher values indicate better localization.
Camera yaw
4∘
8∘
16∘
24∘
32∘
Relative change ratio
3.8×
5.2×
4.8×
10.7×
6.6×
Smaller DiTaR change (% of videos)
82
86
86
100
100
Appendix
Table 7: Viewpoint robustness on ManiSkill. Relative reward-change ratio (ReWiND/DiTaR) and percentage of videos with a smaller reward change for DiTaR.
Figure 10: Viewpoint robustness on ManiSkill. Relative reward changes under synthetic camera yaw (circles) and a second rendered view of the same rollout (stars). The vertical axis is logarithmic; smaller changes indicate greater robustness.
Figure 11: Rewards under visual perturbations. Left two columns: MetaWorld, “press the button,” under 1.25× camera zoom. Right column: ManiSkill, “push the red T-shaped block into place,” under a second camera view. Solid and dashed curves show clean and perturbed rewards.
Figure 12: Reward evolution during policy learning. DiTaR rewards at a fixed task-specific timestep across training stages on 12 MetaWorld-v3 tasks. Solid curves show smoothed traces and dashed lines show linear fits.
Table 8: Task-relevant latent ablation on MetaWorld-v3, with baseline results for comparison. Metrics are defined in Sec. F.3 .
Figure 13: Task-relevant latent ablation. Learning curves on 12 MetaWorld-v3 tasks comparing DiTaR’s task-relevant latents with latents from a single-stage reconstruction-based encoder trained without language conditioning. Both variants use the same conditional rectified-flow architecture and TD reward formulation, with the dynamics model trained separately for each latent representation. DiTaR achieves higher overall success and learns more efficiently.
Figure 14: Cross-dataset latent grouping. Groups of five-frame clips with pairwise cosine similarity of at least 0.90 in the task-relevant latent space. The left and right groups show placing and picking behaviors across different robots and visual settings.
Hyperparameter
Value
Input latent dimension
48
Frames per training window
5
Model dimension
768
Attention heads
12
Encoder blocks
4
Decoder blocks
12
Appendix
Table 9: Architecture and training settings for the latent encoders. The pretrained Wan VAE and T5-base text encoder are frozen throughout representation learning.
Hyperparameter
Value
History input
Five-frame history encoded by the Wan VAE
History tokens / token dimension
512 / 48
Target input
Task-relevant latent of the target clip
Target tokens / token dimension
4 / 32
Text conditioning
Target-only cross-attention; scalar gate initialized to 0
Model dimension
512
Appendix
Table 10: Architecture and training settings for the conditional rectified-flow model.
Hyperparameter
Value
Environment
Action repeat
1
Frame stack
1
Observation size
64×64×3
Episode length
250 environment steps
Per-task training budget
3×106 environment frames
Appendix
Table 11: Online visual RL settings for MetaWorld-v3 and ManiSkill.
Table 12: Task-specific reward and exploration coefficients (λD,λexpl) in Eq. ( 15 ), shared across learned-reward methods. Following the reward-mixing setup of Diffusion Reward ( Huang et al., 2024 ) , we use task-specific reward and exploration coefficients. Tasks sharing the same coefficient pair are grouped in a single row.
Department of Computer Science & Artificial Intelligence, University of Technology Nuremberg, Germany. · TUM School of Computation, Information and Technology, Technical University of Munich, Germany