紧凑型3D高斯溅射的最速下降密度控制
Steepest Descent Density Control for Compact 3D Gaussian Splatting
May 8, 2025
作者: Peihao Wang, Yuehao Wang, Dilin Wang, Sreyas Mohan, Zhiwen Fan, Lemeng Wu, Ruisi Cai, Yu-Ying Yeh, Zhangyang Wang, Qiang Liu, Rakesh Ranjan
cs.AI
摘要
三维高斯泼溅(3DGS)作为一种强大的技术,在实时高分辨率新视角合成领域崭露头角。通过将场景表示为高斯基元的混合体,3DGS利用GPU光栅化管线实现高效的渲染与重建。为了优化场景覆盖并捕捉精细细节,3DGS采用了一种密集化算法来生成额外点云。然而,这一过程常导致点云冗余,引发内存占用过高、性能下降及存储需求激增等问题,对资源受限设备的部署构成了重大挑战。针对这一局限,我们提出了一套理论框架,旨在阐明并改进3DGS中的密度控制机制。我们的分析表明,分裂操作对于逃离鞍点至关重要。通过优化理论方法,我们确立了密集化的必要条件,确定了最小子代高斯数量,找出了最优参数更新方向,并提供了子代不透明度归一化的解析解。基于这些洞见,我们引入了SteepGS,它融入了最陡密度控制这一原则性策略,在保持点云紧凑的同时最小化损失。SteepGS实现了约50%的高斯点减少,且不牺牲渲染质量,显著提升了效率与可扩展性。
English
3D Gaussian Splatting (3DGS) has emerged as a powerful technique for
real-time, high-resolution novel view synthesis. By representing scenes as a
mixture of Gaussian primitives, 3DGS leverages GPU rasterization pipelines for
efficient rendering and reconstruction. To optimize scene coverage and capture
fine details, 3DGS employs a densification algorithm to generate additional
points. However, this process often leads to redundant point clouds, resulting
in excessive memory usage, slower performance, and substantial storage demands
- posing significant challenges for deployment on resource-constrained devices.
To address this limitation, we propose a theoretical framework that demystifies
and improves density control in 3DGS. Our analysis reveals that splitting is
crucial for escaping saddle points. Through an optimization-theoretic approach,
we establish the necessary conditions for densification, determine the minimal
number of offspring Gaussians, identify the optimal parameter update direction,
and provide an analytical solution for normalizing off-spring opacity. Building
on these insights, we introduce SteepGS, incorporating steepest density
control, a principled strategy that minimizes loss while maintaining a compact
point cloud. SteepGS achieves a ~50% reduction in Gaussian points without
compromising rendering quality, significantly enhancing both efficiency and
scalability.