Projecting Gaussian Ellipsoids While Avoiding Affine Projection Approximation

TL;DR

This paper introduces an ellipsoid-based projection method for 3D Gaussian Splatting that reduces errors caused by affine projection approximations, improving rendering quality and scene consistency.

Contribution

The authors propose a novel ellipsoid-based projection technique that avoids affine projection errors in 3D Gaussian Splatting, with a pre-filtering strategy for challenging cases.

Findings

Enhanced rendering quality on benchmark datasets

Reduced artifacts and blurriness in synthesized views

Improved scene consistency in 3D Gaussian Splatting

Abstract

Recently, 3D Gaussian Splatting has dominated novel-view synthesis with its real-time rendering speed and state-of-the-art rendering quality. However, during the rendering process, the use of the Jacobian of the affine approximation of the projection transformation leads to inevitable errors, resulting in blurriness, artifacts and a lack of scene consistency in the final rendered images. To address this issue, we introduce an ellipsoid-based projection method to calculate the projection of Gaussian ellipsoid onto the image plane, which is the primitive of 3D Gaussian Splatting. As our proposed ellipsoid-based projection method cannot handle Gaussian ellipsoids with camera origins inside them or parts lying below $z=0$ plane in the camera space, we designed a pre-filtering strategy. Experiments over multiple widely adopted benchmark datasets show that our ellipsoid-based projection method can enhance the rendering quality of 3D Gaussian Splatting and its extensions.