RU4D-SLAM: Reweighting Uncertainty in Gaussian Splatting SLAM for 4D Scene Reconstruction

CVPR 2026 Findings Track
Yangfan Zhao1* Hanwei Zhang2* Ke Huang3
Qiufeng Wang3 Zhenzhou Shao1† Dengyu Wu4†
*Equal contribution
    Corresponding Author
1Capital Normal University, 2Saarland University
3Xi'an Jiaotong-Liverpool University, 4King's College London
First research result visualization

4D scene reconstruction with RU4D-SLAM. The left side shows the 4D Gaussian map reconstructed by RU4D-SLAM on the Bonn dataset, featuring novel synthesized views that capture the temporal motions (top) and a comparison between the RGB input and RU4D-SLAM rendering at the same pose (bottom). On the right, we compare rendered results from MonoGS, 4DGS-SLAM, and RU4D-SLAM in dynamic scenes. The numbers at the bottom-right of each image denote the PSNR values (higher is better).

Abstract

Combining 3D Gaussian splatting with Simultaneous Localization and Mapping (SLAM) has gained popularity as it enables continuous 3D environment reconstruction during motion. However, existing methods struggle in dynamic environments, particularly moving objects complicate 3D reconstruction and, in turn, hinder reliable tracking. The emergence of 4D reconstruction, especially 4D Gaussian splatting, offers a promising direction for addressing these challenges, yet its potential for 4D-aware SLAM remains largely underexplored. Along this direction, we propose a robust and efficient framework, namely Reweighting Uncertainty in Gaussian Splatting SLAM (RU4D-SLAM) for 4D scene reconstruction, that introduces temporal factors into spatial 3D representation while incorporating uncertainty-aware perception of scene changes, blurred image synthesis, and dynamic scene reconstruction. We enhance dynamic scene representation by integrating motion blur rendering, and improve uncertainty-aware tracking by extending per-pixel uncertainty modeling, which is originally designed for static scenarios, to handle blurred images. Furthermore, we propose a semantic-guided reweighting mechanism for per-pixel uncertainty estimation in dynamic scenes, and introduce a learnable opacity weight to support adaptive 4D mapping. Extensive experiments on standard benchmarks demonstrate that our method substantially outperforms state-of-the-art approaches in both trajectory accuracy and 4D scene reconstruction, particularly in dynamic environments with moving objects and low-quality inputs.