Dynamic Global Illumination for Interactive Gaussian Splatting Scenes in Real Time

We present a real-time pipeline to approximate global illumination in interactive or dynamic scenes, including both 3D Gaussian models and conventional meshes. Building on a formulated surface light transport model for 3D Gaussians, we address key performance challenges through a fast compound stochastic ray-tracing algorithm and a hardware 3D Gaussian rasterizer, and we implement multiple RTGI (real-time global illumination) techniques for 3D Gaussians. Our pipeline enables real-time rendering of interactive scenes featuring editable materials, lights, meshes, and 3D Gaussian models, effectively capturing multi-bounce diffuse and one-bounce glossy light transport. Our approach covers a wide range of dynamic light sources, including area lights, directional lights, and environmental lighting. Comprehensive experimental results demonstrate that our approach can efficiently render global illumination for both 3DGS models and hybrid models combining meshes and 3DGS, all in real time. Our pipeline highlights the potential of 3D Gaussians in real-time global illumination, and offers insights into performance optimization.