RayGauss: Volumetric Gaussian-Based Ray Casting for Photorealistic Novel View Synthesis


WACV 2025


RayGauss
3D Gaussian Splatting

Abstract

Differentiable volumetric rendering-based methods made significant progress in novel view synthesis. On one hand, innovative methods have replaced the Neural Radiance Fields (NeRF) network with locally parameterized structures, enabling high-quality renderings in a reasonable time. On the other hand, approaches have used differentiable splatting instead of NeRF’s ray casting to optimize radiance fields rapidly using Gaussian kernels, allowing for fine adaptation to the scene. However, differentiable ray casting of irregularly spaced kernels has been scarcely explored, while splatting, despite enabling fast rendering times, is susceptible to clearly visible artifacts.

Our work closes this gap by providing a physically consistent formulation of the emitted radiance c and density σ, decomposed with Gaussian functions associated with Spherical Gaussians/Harmonics for all-frequency colorimetric representation. We also introduce a method enabling differentiable ray casting of irregularly distributed Gaussians using an algorithm that integrates radiance fields slab by slab and leverages a BVH structure. This allows our approach to finely adapt to the scene while avoiding splatting artifacts. As a result, we achieve superior rendering quality compared to the state-of-the-art while maintaining reasonable training times and achieving inference speeds of 25 FPS on the Blender dataset. Associated code will be released publicly on GitHub.

Visual Comparisons

Dex-NeRF dataset

Mip-NeRF 360 dataset

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting
RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

Blender dataset

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting
RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

RayGauss
3D Gaussian Splatting

BibTeX

@misc{blanc2024raygaussvolumetricgaussianbasedray,
      title={RayGauss: Volumetric Gaussian-Based Ray Casting for Photorealistic Novel View Synthesis}, 
      author={Hugo Blanc and Jean-Emmanuel Deschaud and Alexis Paljic},
      year={2024},
      eprint={2408.03356},
      archivePrefix={arXiv},
      primaryClass={cs.CV},
      url={https://arxiv.org/abs/2408.03356}, 
}