Identifying Unnecessary 3D Gaussians using Clustering for Fast Rendering of 3D Gaussian Splatting (2402.13827v2)

Abstract: 3D Gaussian splatting (3D-GS) is a new rendering approach that outperforms the neural radiance field (NeRF) in terms of both speed and image quality. 3D-GS represents 3D scenes by utilizing millions of 3D Gaussians and projects these Gaussians onto the 2D image plane for rendering. However, during the rendering process, a substantial number of unnecessary 3D Gaussians exist for the current view direction, resulting in significant computation costs associated with their identification. In this paper, we propose a computational reduction technique that quickly identifies unnecessary 3D Gaussians in real-time for rendering the current view without compromising image quality. This is accomplished through the offline clustering of 3D Gaussians that are close in distance, followed by the projection of these clusters onto a 2D image plane during runtime. Additionally, we analyze the bottleneck associated with the proposed technique when executed on GPUs and propose an efficient hardware architecture that seamlessly supports the proposed scheme. For the Mip-NeRF360 dataset, the proposed technique excludes 63% of 3D Gaussians on average before the 2D image projection, which reduces the overall rendering computation by almost 38.3% without sacrificing peak-signal-to-noise-ratio (PSNR). The proposed accelerator also achieves a speedup of 10.7x compared to a GPU.

• The paper presents a clustering technique that pre-screens unnecessary 3D Gaussians to reduce computational load in rendering.
• It computes optimal Gaussian cluster radii to maintain image fidelity, achieving a 63% reduction without compromising PSNR.
• Experiments and hardware optimization demonstrate significant speed gains, making it valuable for VR, AR, and the Metaverse.

Efficient Rendering via Clustering: Reducing Computational Load in 3D Gaussian Splatting

Introduction to 3D Gaussian Splatting and Its Challenges

Rendering technologies are pivotal in VR, AR, and the Metaverse, offering immersive, high-quality images crucial for these applications. Among various techniques, 3D Gaussian splatting (3D-GS) stands out for its superior speed and image fidelity versus the traditional Neural Radiance Field (NeRF) approaches. 3D-GS employs millions of 3D Gaussians to represent complex scenes, projecting these onto a 2D plane for rendering. Despite its advantages, a significant challenge in 3D-GS is identifying and excluding the "unnecessary" 3D Gaussians for a given viewpoint, leading to high computational overheads.

Proposed Solution: Clustering for Computational Reduction

To tackle the inefficiency, the authors propose a novel method that swiftly identifies unnecessary 3D Gaussians using a clustering-based technique, executed offline. By grouping 3D Gaussians based on proximity before runtime, the approach ensures only clusters potentially influencing the color of the 2D image are processed during rendering, significantly diminishing the computational load.

Key Innovations and Results

The paper introduces several notable contributions to the field of 3D rendering:

• A pioneering technique for pre-screening 3D Gaussians based on the viewer's current perspective, significantly reducing the computational complexity of the 3D-GS rendering process.
• A method to calculate the radius of Gaussians' clusters, considering their influence on the final image, ensuring image quality is not compromised.
• Extensive experimentation across various datasets demonstrating the technique's efficacy, achieving on average a 63% reduction of 3D Gaussians needing processing without affecting the peak signal-to-noise ratio (PSNR).
• The introduction of an optimized hardware architecture that minimizes data packing and scheduling overheads, outperforming GPU implementations in both speed and efficiency metrics.

Theoretical and Practical Implications

This research addresses both theoretical and practical implications of high-fidelity 3D rendering. Theoretically, it provides a robust framework for understanding the relationship between spatial clustering of 3D Gaussians and rendering efficiency. Practically, it offers a scalable solution that can be readily integrated into existing rendering systems, potentially revolutionizing the way complex scenes are rendered in real-time applications.

Speculating on the Future of AI in Rendering

Looking ahead, the methodologies and insights derived from this paper could pave the way for more sophisticated rendering algorithms that dynamically adapt to scene complexity and viewer interaction, further blurring the lines between virtual and physical realities. As AI continues to evolve, its integration into rendering technologies promises not only enhanced visual experiences but also significant optimizations in computational resources, opening the door to new possibilities in digital content creation and consumption.

Summarizing the Impact

In summary, the proposed clustering-based technique for identifying unnecessary 3D Gaussians heralds a significant step forward in rendering technology, offering a path towards more efficient, high-quality image generation. By reducing computational requirements without compromising image quality, this research contributes a valuable tool to the arsenal of developers and researchers working at the cutting edge of virtual reality, augmented reality, and beyond.