Sort-free Gaussian Splatting via Weighted Sum Rendering
Qiqi Hou, Randall Rauwendaal, Zifeng Li, Hoang Le, Farzad Farhadzadeh,, Fatih Porikli, Alexei Bourd, Amir Said
TL;DR
This paper introduces Weighted Sum Rendering for 3D Gaussian Splatting, removing sorting overhead, improving performance, and enabling real-time rendering on mobile devices while maintaining high image quality.
Contribution
It proposes a novel approximation method that eliminates sorting in 3D Gaussian Splatting, enhancing efficiency and suitability for resource-constrained platforms.
Findings
Achieves 1.23x faster rendering on mobile GPU
Maintains competitive image quality with the new method
Removes popping artifacts caused by sorting
Abstract
Recently, 3D Gaussian Splatting (3DGS) has emerged as a significant advancement in 3D scene reconstruction, attracting considerable attention due to its ability to recover high-fidelity details while maintaining low complexity. Despite the promising results achieved by 3DGS, its rendering performance is constrained by its dependence on costly non-commutative alpha-blending operations. These operations mandate complex view dependent sorting operations that introduce computational overhead, especially on the resource-constrained platforms such as mobile phones. In this paper, we propose Weighted Sum Rendering, which approximates alpha blending with weighted sums, thereby removing the need for sorting. This simplifies implementation, delivers superior performance, and eliminates the "popping" artifacts caused by sorting. Experimental results show that optimizing a generalized Gaussian…
Peer Reviews
Decision·ICLR 2025 Poster
- The author provides a clear analysis of the tile-based sort in the vanilla 3DGS, explains its impact on rendering speed, and explains why it is difficult to implement on other devices. - The proposed method speeds up rendering while ensuring rendering quality, and has been verified on consumer mobile devices. - The proposed weighted sum approximation alleviates the *pop* phenomenon caused by inconsistent sorting results under different view-directions in the vanilla 3DGS.
- The proposed method gets rid of the costly sorting, but a more complex weight and view-dependent opacity are used. Although the author points out in the paper that a general scheme for learning scene representations is bound only by the mathematical constraints of the scene model. According to the experimental results in the paper, the use of simple weighted-sum and view-independent opacity cannot achieve satisfactory rendering results. Does this mean that for rendering processes that are not
- The paper aims to address a fundamental bottleneck in 3DGS rendering by proposing a sort-free pipeline, distinguishing itself from previous approaches that primarily focused on reducing Gaussian counts. - The investigation of various weight derivation functions (direct sum-up, exponential weighted, and linear correction weighted) demonstrates a relative comprehensive experimental analysis effort. - Implementation and evaluation on mobile devices effectively demonstrates the practical benefits
- The theoretical foundation for replacing alpha blending with an algebraic function requires stronger justification. While the proposed representation achieves good results, it lacks the physical insights inherent in traditional alpha blending, which models light obstruction during propagation. The introduction of view-dependent opacity appears necessary for acceptable rendering quality, but the paper would benefit from a more rigorous analysis of why this combination works, rather than empiric
**Motivation** * The motivation of this paper is very clear. It clearly illustrates the drawbacks of the sorting requirement of 3DGS and the possible benefit of removing it. Sort-free transparent object rendering is also a well-studied direction in traditional rendering. Combining the algorithms from traditional computer graphics with 3DGS is well-motivated. **Method** * The proposed method transformed the traditional depth-based weighted rendering to a learnable version to better suit the per-
** Motivation ** * As shown in the paper, the sorting step is usually considered slow, but actually contributes to only 25% of the total rendering time. The real problem preventing 3DGS based method from matching the rendering speed of traditional methods is the alpha blending step. Although this paper removes the sorting step, it still needs the per-pixel alpha blending of Gaussians of calculated weights. As a result, the speed improvement is rather insignificant. * Rather than removing the so
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Taxonomy
TopicsVideo Surveillance and Tracking Methods · Advanced Image and Video Retrieval Techniques · Face recognition and analysis
MethodsSoftmax · Attention Is All You Need