3D Gaussian splatting (3DGS) has demonstrated impressive 3D reconstruction performance with explicit scene representations. Given the widespread application of 3DGS in 3D reconstruction and generation tasks, there is an urgent need to protect the copyright of 3DGS assets. However, existing copyright protection techniques for 3DGS overlook the usability of 3D assets, posing challenges for practical deployment. Here we describe WaterGS, the first 3DGS watermarking framework that embeds 3D content in 3DGS itself without modifying any attributes of the vanilla 3DGS. To achieve this, we take a deep insight into spherical harmonics (SH) and devise an importance-graded SH coefficient encryption strategy to embed the hidden SH coefficients. Furthermore, we employ a convolutional autoencoder to establish a mapping between the original Gaussian primitives' opacity and the hidden Gaussian primitives' opacity. Extensive experiments indicate that WaterGS significantly outperforms existing 3D steganography techniques, with 5.31% higher scene fidelity and 3X faster rendering speed, while ensuring security, robustness, and user experience.
三维高斯散点（3D Gaussian Splatting, 3DGS）凭借其显式场景表示，在三维重建和生成任务中表现出色。随着3DGS在各类三维重建和生成任务中的广泛应用，保护3DGS资产版权的需求日益紧迫。然而，现有针对3DGS的版权保护技术往往忽略了3D资产的可用性，给实际部署带来了挑战。 本文提出了WaterGS，这是首个针对3DGS的水印框架，能够在3DGS中嵌入三维内容，而无需修改原始3DGS的任何属性。为实现这一目标，我们深入研究了球谐函数（Spherical Harmonics, SH），设计了一种重要性分级的SH系数加密策略，用于嵌入隐藏的SH系数。此外，我们采用了卷积自编码器（Convolutional Autoencoder），在原始高斯原语的不透明度与隐藏高斯原语的不透明度之间建立了映射关系。 大量实验表明，WaterGS显著优于现有的三维隐写技术，其场景保真度提高了5.31%，渲染速度提升了3倍，同时确保了水印的安全性、鲁棒性以及用户体验。这一框架为保护3DGS资产版权提供了一种高效、实用的解决方案。