@inproceedings{
guo2024prtgs,
title={{PRTGS}: Precomputed Radiance Transfer of Gaussian Splats for Real-Time High-Quality Relighting},
author={Yijia Guo and Yuanxi Bai and Liwen Hu and Guo Ziyi and Mianzhi Liu and Yu Cai and Tiejun Huang and Lei Ma},
booktitle={ACM Multimedia 2024},
year={2024},
url={https://openreview.net/forum?id=SNwk8uqmqs}
}
We proposed Precomputed Radiance Transfer of Gaussian Splats (PRTGS), a real-time high-quality relighting method for Gaussian splats in low-frequency lighting environments that captures soft shadows and interreflections by precomputing 3D Gaussian splats' radiance transfer. 
Existing studies have demonstrated that 3D Gaussian splatting (3DGS) outperforms neural fields in efficiency for dynamic lighting scenarios. However, the current relighting method based on 3DGS still struggling in computing high-quality shadow and indirect illumination in real time for dynamic light, leading to unrealistic rendering results. We solve this problem by precomputing the expensive transport simulations required for complex transfer functions like shadowing, the resulting transfer functions are represented as dense sets of vectors or matrices for every Gaussian splat. We introduce distinct precomputing methods tailored for training and rendering stages, along with unique ray tracing and indirect lighting precomputation techniques for 3D Gaussian splats to accelerate training speed and compute accurate indirect lighting related to environment light. Experimental analyses demonstrate that our approach achieves state-of-the-art visual quality while maintaining competitive training times and importantly allows high-quality real-time (30+ fps) relighting for dynamic light and relatively complex scenes at 1080p resolution.
PRTGS: Precomputed Radiance Transfer of Gaussian Splats for Real-Time High-Quality Relighting
Yijia Guo Yuanxi Bai Liwen Hu Guo Ziyi Mianzhi Liu Yu Cai Tiejun Huang Lei Ma