# Unifying Appearance Codes and Bilateral Grids for Driving Scene Gaussian Splatting

NeurIPS 2025 Conference Submission #1353

### Table of Contents

- Abstract
- Video Demos
- Textual Supplementary Material

## TL;DR: we introduced Multi-Scale Bilateral Grids that unifies appearance codes and bilateral grids, significantly improves geometric accuracy in dynamic, decoupled autonomous driving scene reconstruction.

## Abstract

Neural rendering techniques, including NeRF and Gaussian Splatting (GS), rely on photometric consistency to produce high-quality reconstructions. However, in real-world scenarios, it is challenging to guarantee perfect photometric consistency in acquired images. Appearance codes have been widely used to address this issue, but their modeling capability is limited, as a single code is applied to the entire image. Recently, the bilateral grid was introduced to perform pixel-wise color mapping, but it is difficult to optimize and constrain effectively. In this paper, we propose a novel multi-scale bilateral grid that unifies appearance codes and bilateral grids. We demonstrate that this approach significantly improves geometric accuracy in dynamic, decoupled autonomous driving scene reconstruction, outperforming both appearance codes and bilateral grids. This is crucial for autonomous driving, where accurate geometry is important for obstacle avoidance and control. Our method shows strong results across four datasets: Waymo, NuScenes, Argoverse, and PandaSet. We further demonstrate that the improvement in geometry is driven by the multi-scale bilateral grid, which effectively reduces floaters caused by photometric inconsistency.

## Video Demos

#### Rendering results comparing our method with the Baseline.
Baseline results are reconstructed using Omnire (ICLR 2025 Spotlight).
Scenes are from nuScenes, Waymo, PandaSet, and Argoverse.

Due to file size limitations, videos are compressed and quality might be affected.

## Textual Supplementary Material