Anti-Aliased 2D Gaussian Splatting

TL;DR

The paper introduces AA-2DGS, an anti-aliased 2D Gaussian Splatting method that reduces artifacts during rendering at different scales, improving view synthesis and surface reconstruction quality.

Contribution

It proposes a novel anti-aliasing formulation for 2D Gaussian Splatting, including a world-space smoothing kernel and an object-space Mip filter, to enhance rendering quality across scales.

Findings

Significantly reduces aliasing artifacts during zooming.

Maintains geometric accuracy while improving rendering quality.

Effective anti-aliasing applied directly in local splat space.

Abstract

2D Gaussian Splatting (2DGS) has recently emerged as a promising method for novel view synthesis and surface reconstruction, offering better view-consistency and geometric accuracy than volumetric 3DGS. However, 2DGS suffers from severe aliasing artifacts when rendering at different sampling rates than those used during training, limiting its practical applications in scenarios requiring camera zoom or varying fields of view. We identify that these artifacts stem from two key limitations: the lack of frequency constraints in the representation and an ineffective screen-space clamping approach. To address these issues, we present AA-2DGS, an anti-aliased formulation of 2D Gaussian Splatting that maintains its geometric benefits while significantly enhancing rendering quality across different scales. Our method introduces a world-space flat smoothing kernel that constrains the frequency content of 2D Gaussian primitives based on the maximal sampling frequency from training views, effectively eliminating high-frequency artifacts when zooming in. Additionally, we derive a novel object-space Mip filter by leveraging an affine approximation of the ray-splat intersection mapping, which allows us to efficiently apply proper anti-aliasing directly in the local space of each splat.