Ref-GS: Directional Factorization for 2D Gaussian Splatting

TL;DR

Ref-GS introduces a directional factorization technique for 2D Gaussian splatting that enhances photorealistic, view-dependent rendering and accurate geometry recovery by incorporating directional encoding, surface roughness, and efficient geometry-lighting factorization.

Contribution

The paper presents a novel directional encoding and a spherical Mip-grid for Gaussian splatting, improving realism and geometry accuracy in view-dependent rendering.

Findings

Achieves superior photorealistic rendering in open-world scenes.

Effectively recovers geometry with high accuracy.

Reduces renderer overhead through efficient geometry-lighting factorization.

Abstract

In this paper, we introduce Ref-GS, a novel approach for directional light factorization in 2D Gaussian splatting, which enables photorealistic view-dependent appearance rendering and precise geometry recovery. Ref-GS builds upon the deferred rendering of Gaussian splatting and applies directional encoding to the deferred-rendered surface, effectively reducing the ambiguity between orientation and viewing angle. Next, we introduce a spherical Mip-grid to capture varying levels of surface roughness, enabling roughness-aware Gaussian shading. Additionally, we propose a simple yet efficient geometry-lighting factorization that connects geometry and lighting via the vector outer product, significantly reducing renderer overhead when integrating volumetric attributes. Our method achieves superior photorealistic rendering for a range of open-world scenes while also accurately recovering geometry.