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 on the image plane, witch 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 using our ellipsoid-based projection method can enhance the rendering quality of 3D Gaussian Splatting and its extensions.
近年来，3D Gaussian Splatting 凭借其实时渲染速度和最先进的渲染质量在新视图合成领域占据了主导地位。然而，在渲染过程中，使用投影变换的仿射近似雅可比矩阵不可避免地引入误差，导致最终渲染图像出现模糊、伪影以及场景一致性不足等问题。 为了解决这一问题，我们提出了一种基于椭球的投影方法，用于计算 3D Gaussian Splatting 中高斯椭球在图像平面上的投影。相比于传统方法，该投影更接近真实投影，减少了误差。然而，由于该方法无法处理相机原点位于高斯椭球内部或高斯椭球部分位于相机空间  平面以下的情况，我们设计了一种预过滤策略以应对这些特殊情况。 在多个广泛采用的基准数据集上的实验表明，基于椭球的投影方法能够显著提升 3D Gaussian Splatting 及其扩展方法的渲染质量。