High-quality Surface Reconstruction using Gaussian Surfels

TL;DR

This paper introduces Gaussian surfels, a novel point-based surface representation that improves surface reconstruction by combining Gaussian points with surfel properties, enhanced by a self-supervised normal-depth consistency loss and volumetric aggregation.

Contribution

The paper presents Gaussian surfels with a new flattening technique and a self-supervised loss, advancing surface reconstruction accuracy and stability over existing methods.

Findings

Outperforms state-of-the-art neural volume and point-based rendering methods.

Improves surface alignment and reconstruction stability.

Effectively mitigates issues from highlights and background noise.

Abstract

We propose a novel point-based representation, Gaussian surfels, to combine the advantages of the flexible optimization procedure in 3D Gaussian points and the surface alignment property of surfels. This is achieved by directly setting the z-scale of 3D Gaussian points to 0, effectively flattening the original 3D ellipsoid into a 2D ellipse. Such a design provides clear guidance to the optimizer. By treating the local z-axis as the normal direction, it greatly improves optimization stability and surface alignment. While the derivatives to the local z-axis computed from the covariance matrix are zero in this setting, we design a self-supervised normal-depth consistency loss to remedy this issue. Monocular normal priors and foreground masks are incorporated to enhance the quality of the reconstruction, mitigating issues related to highlights and background. We propose a volumetric cutting method to aggregate the information of Gaussian surfels so as to remove erroneous points in depth maps generated by alpha blending. Finally, we apply screened Poisson reconstruction method to the fused depth maps to extract the surface mesh. Experimental results show that our method demonstrates superior performance in surface reconstruction compared to state-of-the-art neural volume rendering and point-based rendering methods.