OccGS: Zero-shot 3D Occupancy Reconstruction with Semantic and Geometric-Aware Gaussian Splatting

Obtaining semantic 3D occupancy from raw sensor data without manual annotations remains an essential yet challenging task. While prior works have approached this as a perception prediction problem, we formulate it as scene-aware 3D occupancy reconstruction with geometry and semantics. In this work, we propose OccGS, a novel 3D Occupancy reconstruction framework utilizing Semantic and Geometric-Aware Gaussian Splatting in a zero-shot manner. Leveraging semantics extracted from vision-language models and geometry guided by LiDAR points, OccGS constructs Semantic and Geometric-Aware Gaussians from raw multisensor data. We also develop a cumulative Gaussian-to-3D voxel splatting method for reconstructing occupancy from the Gaussians. OccGS performs favorably against self-supervised methods in occupancy prediction, achieving comparable performance to fully supervised approaches and achieving state-of-the-art performance on zero-shot semantic 3D occupancy estimation.