Joint Semantic and Rendering Enhancements in 3D Gaussian Modeling with Anisotropic Local Encoding
Jingming He, Chongyi Li, Shiqi Wang, Sam Kwong
TL;DR
The paper tackles the limitation of relying on 2D supervision and gradient-only cues in 3D Gaussian Splatting by introducing a joint semantic-rendering framework. It leverages an anisotropic 3D Gaussian local encoding based on the Laplace–Beltrami operator to capture directional local geometry and refines semantic features accordingly, while also adaptively allocating Gaussians and SH levels using local semantic and shape cues. A cross-scene knowledge transfer module maintains a pattern basis to reuse learned shape patterns across scenes, accelerating convergence and improving robustness. Experiments on Replica, ScanNet, and Deep Blending show improved segmentation mIoU and rendering PSNR with maintained high frame rates, demonstrating practical gains in dense 3D scene understanding and rendering efficiency.
Abstract
Recent works propose extending 3DGS with semantic feature vectors for simultaneous semantic segmentation and image rendering. However, these methods often treat the semantic and rendering branches separately, relying solely on 2D supervision while ignoring the 3D Gaussian geometry. Moreover, current adaptive strategies adapt the Gaussian set depending solely on rendering gradients, which can be insufficient in subtle or textureless regions. In this work, we propose a joint enhancement framework for 3D semantic Gaussian modeling that synergizes both semantic and rendering branches. Firstly, unlike conventional point cloud shape encoding, we introduce an anisotropic 3D Gaussian Chebyshev descriptor using the Laplace-Beltrami operator to capture fine-grained 3D shape details, thereby distinguishing objects with similar appearances and reducing reliance on potentially noisy 2D guidance. In addition, without relying solely on rendering gradient, we adaptively adjust Gaussian allocation and spherical harmonics with local semantic and shape signals, enhancing rendering efficiency through selective resource allocation. Finally, we employ a cross-scene knowledge transfer module to continuously update learned shape patterns, enabling faster convergence and robust representations without relearning shape information from scratch for each new scene. Experiments on multiple datasets demonstrate improvements in segmentation accuracy and rendering quality while maintaining high rendering frame rates.
