Generalizable & Relightable: The Future of High-Fidelity 3D Human Avatars with Gaussian Splatting

By Yipengjing Sun, Shengping Zhang, Chenyang Wang, Shunyuan Zheng, Zonglin Li, Xiangyang Ji


Published on November 24, 2025| Vol. 1, Issue No. 1

Summary

The presented paper introduces GRGS, a novel 3D Gaussian framework designed for high-fidelity novel view synthesis of humans under diverse lighting conditions. Moving beyond per-character optimization or physics-ignorant methods, GRGS employs a feed-forward, fully supervised approach that projects geometric, material, and illumination cues from multi-view 2D observations into 3D Gaussian representations. Key components include a Lighting-robust Geometry Refinement (LGR) module, trained on synthetically relit data to predict precise depth and surface normals, and a Physically Grounded Neural Rendering (PGNR) module that integrates neural predictions with physics-based shading, enabling editable relighting with realistic shadows and indirect illumination. Furthermore, the system incorporates a 2D-to-3D projection training scheme using differentiable supervision from ambient occlusion, direct, and indirect lighting maps, which significantly reduces the computational burden of ray tracing. Extensive experiments confirm GRGS's superior visual quality, geometric consistency, and generalization capabilities across various characters and lighting scenarios.

Why It Matters

This research marks a significant leap forward in the creation and deployment of digital humans, addressing two critical bottlenecks: generalizability and realistic relighting. For AI professionals, GRGS is not just another rendering technique; it represents a fundamental shift in how high-fidelity 3D human assets can be generated and utilized at scale. The ability to generalize across different characters without per-character optimization dramatically reduces the prohibitive costs and time associated with creating diverse digital populations for virtual worlds, games, or augmented reality experiences. This means content creators can rapidly populate virtual environments with unique, high-quality human avatars that previously required extensive manual effort or dedicated data collection for each individual.

Furthermore, the "relightable" aspect is a game-changer for realism and immersion. Static, pre-baked lighting is a major limitation in dynamic environments. GRGS's physically grounded neural rendering, which supports editable relighting with accurate shadows and indirect illumination, ensures that digital humans integrate seamlessly into any lighting condition-whether it's a game engine's real-time lighting, an AR scene reflecting real-world illumination, or a cinematic production demanding precise lighting control. This pushes the boundaries of photorealism, making digital humans indistinguishable from real ones in varying light. The clever integration of Gaussian Splatting, a cutting-edge fast rendering technique, with physics-based shading and a computationally efficient 2D-to-3D projection scheme, positions GRGS as a cornerstone technology for the next generation of virtual reality, augmented reality, gaming, and digital media, democratizing access to high-fidelity, dynamic digital human representations.

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