Novel view synthesis has demonstrated impressive progress recently, with 3D Gaussian splatting (3DGS) offering efficient training time and photorealistic real-time rendering. However, reliance on Cartesian coordinates limits 3DGS's performance on distant objects, which is important for reconstructing unbounded outdoor environments. We found that, despite its ultimate simplicity, using homogeneous coordinates, a concept on the projective geometry, for the 3DGS pipeline remarkably improves the rendering accuracies of distant objects. We therefore propose Homogeneous Gaussian Splatting (HoGS) incorporating homogeneous coordinates into the 3DGS framework, providing a unified representation for enhancing near and distant objects. HoGS effectively manages both expansive spatial positions and scales particularly in outdoor unbounded environments by adopting projective geometry principles. Experiments show that HoGS significantly enhances accuracy in reconstructing distant objects while maintaining high-quality rendering of nearby objects, along with fast training speed and real-time rendering capability. Our implementations are available on our project page https://kh129.github.io/hogs/.

翻译：近年来，新视角合成技术取得了显著进展，其中3D高斯点绘制（3DGS）以其高效的训练时间和照片级真实的实时渲染能力备受关注。然而，对笛卡尔坐标系的依赖限制了3DGS在远距离物体上的表现，而这对于重建无界户外环境至关重要。我们发现，尽管方法极其简洁，将射影几何中的齐次坐标概念引入3DGS流程，能显著提升远距离物体的渲染精度。为此，我们提出齐次高斯点绘制（HoGS），将齐次坐标融入3DGS框架，为增强近处和远处物体的表现提供了统一表征。通过采用射影几何原理，HoGS能有效处理户外无界环境中尤其突出的广阔空间位置与尺度变化。实验表明，HoGS在保持近处物体高质量渲染的同时，显著提升了远距离物体的重建精度，并兼具快速训练与实时渲染能力。我们的实现代码已在项目页面https://kh129.github.io/hogs/公开。