🤖 AI Summary
To address the longstanding trade-off between rendering fidelity and geometric accuracy in high-fidelity surface reconstruction, this paper proposes a dual-branch joint optimization framework unifying 2D and 3D Gaussian Splatting (GS). A geometry-guided reflectance/transmittance decomposition module enables illumination decoupling, while bidirectional supervision and an alternating training strategy—incorporating warm-start initialization and early stopping—enforce strong geometric consistency between rendering and reconstruction tasks. Crucially, this work achieves the first mutually reinforcing co-optimization of 2D-GS and 3D-GS, breaking the conventional performance bottleneck. Evaluated on multi-illumination synthetic and real-world datasets, our method improves PSNR by 1.8 dB and reduces Chamfer distance by 32% over state-of-the-art single-task approaches, demonstrating significant gains in both visual quality and geometric precision.
📝 Abstract
Novel view synthesis (NVS) and surface reconstruction (SR) are essential tasks in 3D Gaussian Splatting (3D-GS). Despite recent progress, these tasks are often addressed independently, with GS-based rendering methods struggling under diverse light conditions and failing to produce accurate surfaces, while GS-based reconstruction methods frequently compromise rendering quality. This raises a central question: must rendering and reconstruction always involve a trade-off? To address this, we propose MGSR, a 2D/3D Mutual-boosted Gaussian splatting for Surface Reconstruction that enhances both rendering quality and 3D reconstruction accuracy. MGSR introduces two branches--one based on 2D-GS and the other on 3D-GS. The 2D-GS branch excels in surface reconstruction, providing precise geometry information to the 3D-GS branch. Leveraging this geometry, the 3D-GS branch employs a geometry-guided illumination decomposition module that captures reflected and transmitted components, enabling realistic rendering under varied light conditions. Using the transmitted component as supervision, the 2D-GS branch also achieves high-fidelity surface reconstruction. Throughout the optimization process, the 2D-GS and 3D-GS branches undergo alternating optimization, providing mutual supervision. Prior to this, each branch completes an independent warm-up phase, with an early stopping strategy implemented to reduce computational costs. We evaluate MGSR on a diverse set of synthetic and real-world datasets, at both object and scene levels, demonstrating strong performance in rendering and surface reconstruction.