ReWAM
Rethinking Representations
for World-Action Modeling

Let the policy shape what the representation encodes,
and the world model learn how it evolves.

Haoyi Jiang1,*, Liu Liu3,†, Xinjiang Wang3, Zhihao Sun4, Zequn Chen3, Sen Wang5, Xinjie Wang3, Xia Chen3,
Jingfeng Yao1, Weiheng Zhao1, Shanglin Yuan1, Zhizhong Su3, Wei Sui2, Wenyu Liu1, Xinggang Wang1,‡
1 Huazhong University of Science & Technology2 D-Robotics3 Horizon Robotics4 Fudan University5 Xi’an Jiaotong University

* Intern at D-Robotics   † Project leader   ‡ Corresponding author

Comparison of Video-VAE latents, frozen DINO features, and ReWAM. ReWAM calibrates DINO features and forms compact states through a Temporal Representation Bottleneck shaped by action-loss gradients.
Overview of representations for world-action modeling. ReWAM forms compact world states from calibrated DINO features through a Temporal Representation Bottleneck (TRB). Action-Grounded Representation Shaping (AGRS) updates the TRB through action-loss gradients, while the world model learns state transitions.
93.6%

RoboTwin 2.0 success

Both clean and random settings
12.29

RoboDojo average score

With ~600 hours of embodied pre-training
91.7%

Real-robot success

55 successful trials out of 60
0

Generative video pre-training

Built on frozen DINOv3 features

THE CENTRAL QUESTION

What makes a good
world-action representation?

World-action models need a shared space that supports both predicting future observations and choosing robot actions. Visual reconstruction quality alone does not tell us how useful that space is for control.

ReWAM starts from frozen DINO features, calibrates them for dynamics learning, and organizes them into temporal world states. The action objective shapes these states; the world objective learns their evolution. This division of roles supports strong robot policies without generative video pre-training.

Read the full study

THE METHOD

Perception, organized for action.

Three components turn perceptual features into a space for prediction and control.

01 / CALIBRATE

Feature Calibration

Multi-layer aggregation, normalization, and a representation-aware noise schedule prepare frozen DINO features for diffusion-based dynamics modeling.

02 / COMPRESS

Temporal Representation Bottleneck

A trainable bottleneck combines paired frames across camera views into compact, 128-dimensional world-state tokens.

03 / GROUND
Action-loss gradients update the TRB; world-loss gradients stop before the TRB. Action lossTRBWorld loss updatesstop-gradient

Action-Grounded Representation Shaping

Only action-loss gradients update the bottleneck. World-loss gradients stop at the representations, allowing the world model to learn their dynamics.

SIMULATION BENCHMARKS

From representations to results.

Experimental details ↗

RoboTwin 2.0

50 tasks · 100 evaluation episodes per task and setting

93.6%Clean
93.6%Random

No embodied pre-training or generative video pre-training. Main results use five training epochs.

RoboDojo

Five capability categories · 35 training tasks

Average results with and without embodied pre-training
Method / embodied pre-trainingScore ↑Success ↑
Fast-WAM / none3.482.03%
ReWAM / none9.425.82%
Fast-WAM / ~600 h10.956.80%
ReWAM / ~600 h12.298.28%

The two ~600 h models use the same embodied pre-training data.

Why does representation design matter?

RoboTwin 2.0 success rates under a matched one-epoch budget. These experiments use a different budget from the main results above.

RepresentationClean ↑Random ↑
Raw DINO features71.00%71.54%
Feature Calibration83.90%83.03%
Fixed random temporal projection86.76%85.94%
ReWAM with AGRS90.70%89.12%

ON PHYSICAL HARDWARE

Three tasks. A bimanual robot.

Evaluated on the Piper platform over 20 trials per task, following embodied pre-training and task-specific post-training.

BUILD ON THIS WORK

Citation

@article{jiang2026rewam,
  title={Rethinking Representations for World-Action Modeling},
  author={Haoyi Jiang and Liu Liu and Xinjiang Wang and Zhihao Sun and Zequn Chen and Sen Wang and Xinjie Wang and Xia Chen and Jingfeng Yao and Weiheng Zhao and Shanglin Yuan and Zhizhong Su and Wei Sui and Wenyu Liu and Xinggang Wang},
  journal={arXiv preprint arXiv:2609.38163},
  year={2026},
  url={https://arxiv.org/abs/2609.38163}
}