Grid4D: 4D Decomposed Hash Encoding for High-Fidelity Dynamic Gaussian Splatting
July 27, 2025 ยท View on GitHub
[NeurIPS 2024] Official implementation of "Grid4D: 4D Decomposed Hash Encoding for High-Fidelity Dynamic Gaussian Splatting"

Dataset
In our paper, we use the following datasets.
- D-NeRF: a synthetic monocular dataset which contains 8 scenes.
- HyperNeRF: a real-world dataset captured by one or two cameras.
- Neu3D: a real-world dataset captured by multiple cameras with fixed poses.
We follow the experimental setting of 4D-GS for the real-world HyperNeRF and Neu3D dataset, and thank very much for their excellent work.
For the HyperNeRF dataset, we use the points.npy provided by the dataset to initialize the Gaussians, mainly following the Deformable-3D-Gaussians.
For the Neu3D dataset, we use the points3D_downsample2.ply generated by ColMap used in the 4D-GS to initialize the Gaussians.
Pipeline

Install
git clone https://github.com/JiaweiXu8/Grid4D.git
cd Grid4D
conda env create -f environment.yaml
conda activate Grid4D
# require CUDA 11.X
pip install -e ./submodules/depth-diff-gaussian-rasterization
pip install -e ./submodules/simple-knn
Run
train
python train.py -s <scene path> -m <output path> --conf ./arguments/<dataset>/<scene>.py
render
python render.py --conf ./arguments/<dataset>/<scene>.py -m <output path>
You can use the best checkpoint during the training process by adding --iteration best to get better results.
evaluation
python metrics.py -m <output path>
Results

Acknowledgments
This framework has been adapted from Gaussian Splatting, Deformable-3D-Gaussians. The implementation of hash encoding is heavily based on ObjectSDF++. We sincerely appreciate the excellent works of these authors.
@Article{kerbl3Dgaussians,
author = {Kerbl, Bernhard and Kopanas, Georgios and Leimk{\"u}hler, Thomas and Drettakis, George},
title = {3D Gaussian Splatting for Real-Time Radiance Field Rendering},
journal = {ACM Transactions on Graphics},
number = {4},
volume = {42},
month = {July},
year = {2023},
url = {https://repo-sam.inria.fr/fungraph/3d-gaussian-splatting/}
}
@article{yang2023deformable3dgs,
title={Deformable 3D Gaussians for High-Fidelity Monocular Dynamic Scene Reconstruction},
author={Yang, Ziyi and Gao, Xinyu and Zhou, Wen and Jiao, Shaohui and Zhang, Yuqing and Jin, Xiaogang},
journal={arXiv preprint arXiv:2309.13101},
year={2023}
}
BibTex
@article{xu2024grid4d,
title={{Grid4D}: {4D} Decomposed Hash Encoding for High-Fidelity Dynamic Gaussian Splatting},
author={Jiawei, Xu and Zexin, Fan and Jian, Yang and Jin, Xie},
journal={The Thirty-eighth Annual Conference on Neural Information Processing Systems},
year={2024},
}