RT-Splatting: Joint Reflection-Transmission Modeling with Gaussian Splatting

2026-05-18

AI Summary

Existing 3D Gaussian splatting methods often suffer from blurred reflections or occluded transmissions when rendering translucent specular surfaces that exhibit both complex reflectance and sharp transmission, due to the entanglement of geometric occupancy and optical opacity. This work proposes RT-Splatting, a novel framework that decouples geometric occupancy from optical opacity to construct a unified surface–volume hybrid representation. A dedicated hybrid renderer is introduced to separately handle high-frequency reflections and clear transmissions. Furthermore, we innovatively incorporate a Specular-Aware Gradient Gating mechanism that effectively suppresses interference gradients from specular regions on the transmission branch, significantly mitigating ghosting artifacts. The method achieves state-of-the-art real-time, high-fidelity rendering on challenging translucent scenes while supporting flexible editing.

Abstract

3D Gaussian Splatting (3DGS) enables real-time novel view synthesis with high visual quality. However, existing methods struggle with semi-transparent specular surfaces that exhibit both complex reflections and clear transmission, often producing blurry reflections or overly occluded transmission. To address this, we present RT-Splatting, a framework that disentangles each Gaussian's geometric occupancy from its optical opacity. This factorization yields a unified surface-volume scene representation with a single set of Gaussian primitives. Our hybrid renderer interprets this representation both as a surface to capture high-frequency reflections and as a volume to preserve clear transmission. To mitigate the ambiguity in jointly optimizing reflection and transmission, we introduce Specular-Aware Gradient Gating, which suppresses misleading gradients from highly specular regions into the transmission branch, effectively reducing distracting floaters. Experiments on challenging semi-transparent scenes show that RT-Splatting achieves state-of-the-art performance, delivering high-fidelity reflections and clear transmission with real-time rendering. Moreover, our factorization naturally enables flexible scene editing. The project page is available at https://sjj118.github.io/RT-Splatting.

Problem

• semi-transparent surfaces
• specular reflections
• clear transmission
• 3D Gaussian Splatting
• novel view synthesis

Innovation

• Gaussian Splatting
• Reflection-Transmission Modeling
• Specular-Aware Gradient Gating
• Surface-Volume Representation
• Real-time Rendering