3D Gaussian Splats (3DGS) have proven a versatile rendering primitive, both for inverse rendering as well as real-time exploration of scenes. In these applications, coherence across camera frames and multiple views is crucial, be it for robust convergence of a scene reconstruction or for artifact-free fly-throughs. Recent work started mitigating artifacts that break multi-view coherence, including popping artifacts due to inconsistent transparency sorting and perspective-correct outlines of (2D) splats. At the same time, real-time requirements forced such implementations to accept compromises in how transparency of large assemblies of 3D Gaussians is resolved, in turn breaking coherence in other ways. In our work, we aim at achieving maximum coherence, by rendering fully perspective-correct 3D Gaussians while using a high-quality approximation of accurate blending, hybrid transparency, on a per-pixel level, in order to retain real-time frame rates. Our fast and perspectively accurate approach for evaluation of 3D Gaussians does not require matrix inversions, thereby ensuring numerical stability and eliminating the need for special handling of degenerate splats, and the hybrid transparency formulation for blending maintains similar quality as fully resolved per-pixel transparencies at a fraction of the rendering costs. We further show that each of these two components can be independently integrated into Gaussian splatting systems. In combination, they achieve up to 2$\times$ higher frame rates, 2$\times$ faster optimization, and equal or better image quality with fewer rendering artifacts compared to traditional 3DGS on common benchmarks.

翻译：三维高斯溅射（3DGS）已被证明是一种通用的渲染基元，既适用于逆向渲染，也适用于场景的实时探索。在这些应用中，相机帧间和多视图间的一致性至关重要，无论是为了场景重建的稳健收敛，还是为了无伪影的穿行体验。近期研究开始缓解破坏多视图一致性的伪影，包括因透明度排序不一致导致的突变伪影以及（二维）溅射轮廓的透视校正问题。与此同时，实时性要求迫使此类实现在处理大规模三维高斯集合的透明度合成时做出妥协，进而以其他方式破坏一致性。在本工作中，我们旨在实现最大程度的一致性：通过渲染完全透视校正的三维高斯，同时在像素级别采用高质量近似精确混合的混合透明度方法，以保持实时帧率。我们提出的快速且透视精确的三维高斯求值方法无需矩阵求逆，从而确保数值稳定性并消除对退化溅射进行特殊处理的需求；而用于混合的混合透明度公式能以极低的渲染成本保持与完全解析的逐像素透明度相近的质量。我们进一步证明，这两个组件均可独立集成到高斯溅射系统中。结合使用时，在常见基准测试中，相较于传统3DGS，我们的方法可实现高达2倍的帧率提升、2倍的优化加速，并在减少渲染伪影的同时获得同等或更优的图像质量。