ReflectVLM

Official implementation of "Reflective Planning: Vision-Language Models for Multi-Stage Long-Horizon Robotic Manipulation".

Paper | Website | Video | Hugging Face

Contents

• Installation
• Simulation environment
• Policy evaluation
• Policy training
• Citation
• License & Acknowledgements

Installation

1. Clone this repository

git clone git@github.com:yunhaif/reflect-vlm.git
cd reflect-vlm

2. Install packages

conda create -n reflectvlm python=3.9 -y
conda activate reflectvlm
pip install -e .

3. (Optional) Install additional packages if you want to train VLM policies.

pip install -e ".[train]"
pip install flash-attn --no-build-isolation

Simulation environment

Interacting with the environment

We provide a simple script to play with the simulation environment.

python scripts/interact.py

This will generate a task in MuJoCo with interactive visualization. You can interact with the environment by typing the actions. Just launch the script and follow the instructions — it works on Mac too!

mjpython scripts/interact.py    # Use `mjpython` to launch the script if you are on macOS

Generating as many tasks as you want

The task generated by our procedural task generator is controlled by a seed. You can generate as many tasks as you want by simply changing the environment seed!

python scripts/interact.py --env_seed 1000001

Policy evaluation

Evaluating our checkpoints

Models are available on Hugging Face, including:

• ReflectVLM-llava-v1.5-13b-base: a base VLM policy trained on a fixed expert dataset.
• ReflectVLM-llava-v1.5-13b-post-trained: the VLM policy trained with our post-training strategy with reflection mechanism.
• ReflectVLM-diffusion: the diffusion dynamics model.

We provide scripts to run evaluation on the 100 procedurally-generated test tasks. Models will be automatically downloaded from Hugging Face.

To evaluate the base policy:

bash scripts/eval_base_vlm.sh

To evaluate our post-trained policy with reflection:

bash scripts/eval_reflect_vlm.sh {sim|diffusion}

Choose either sim or diffusion as the dynamics model used in the reflection mechanism.

Building your own agent

You can add your own agent under the agent folder. Create a new class and implement the act() method to process observation and get action.

class MyAgent:
    def __init__(self, ...):
        ... # initialize model etc.

    def act(self, img, goal_img, inp):
        """
        Args:
            img: the current image
            goal_img: the goal image
            inp: the input prompt
        Returns:
            action: a string of action
        """
        action = ...    # get action from model
        return action

Policy training

Coming soon...

Diffusion model

The script scripts/diffusion_demo.py can be used to test diffusion generation:

python scripts/diffusion_demo.py 

We provide some sample images under assets/images/diffusion_examples.

Citation

If you find our work useful in your research, please consider citing with the following BibTeX:

@misc{feng2025reflective,
  title={Reflective Planning: Vision-Language Models for Multi-Stage Long-Horizon Robotic Manipulation}, 
  author={Yunhai Feng and Jiaming Han and Zhuoran Yang and Xiangyu Yue and Sergey Levine and Jianlan Luo},
  year={2025},
  eprint={2502.16707},
  archivePrefix={arXiv},
  primaryClass={cs.RO},
  url={https://arxiv.org/abs/2502.16707}, 
}

License & Acknowledgements

This repository is licensed under the MIT license. LLaVA is licensed under the Apache 2.0 license.
Part of the simulation environment is adapted from Metaworld and mjctrl.