GRay: Ray Tracing 3D Gaussians Near the Speed of Splats

GRay is a new ray tracer for 3D Gaussians that tries to close the long-standing performance gap between ray-traced and rasterized Gaussian rendering. The paper argues that the usual complaint against ray tracing—too much work per frame—changes when your scene is made of many tiny Gaussians, because only primitives actually hit by a ray need to be evaluated.

That matters because 3D Gaussian Splatting has been popular largely due to speed, but the authors show that dense initialization, which tends to hurt rasterization, can help ray tracing instead. In their results, GRay renders nearly 4x faster and optimizes nearly 10x faster than 3DGRT, with similar quality, while remaining competitively fast relative to 3DGS itself, though at somewhat lower quality.

The practical takeaway for engine and rendering developers is that representation choice and scene density can flip the usual performance tradeoffs. If your pipeline already uses Gaussian primitives or similar dense point-based representations, this suggests ray tracing may be worth revisiting instead of assuming splatting is always the faster path.

The paper was submitted to arXiv on 29 Jun 2026 by Yohan Poirier-Ginter, Jean-François Lalonde, and George Drettakis. Code is available, which makes this more than a theoretical result and gives teams something concrete to benchmark against their own content and hardware.