RegionPLC: Regional Point-Language Contrastive Learning for Open-World 3D Scene Understanding
Authors: Jihan Yang, Runyu Ding, Weipeng Deng, Zhe Wang, Xiaojuan Qi

We propose a lightweight and scalable Regional Point-Language Contrastive learning framework namely RegionPLC for open-world 3D scene understanding aiming to identify and recognize open-set objects and categories. Specifically based on our empirical studies we introduce a 3D-aware SFusion strategy that fuses 3D vision-language pairs derived from multiple 2D foundation models yielding high-quality dense region-level language descriptions without human 3D annotations. Subsequently we devise a region-aware point-discriminative contrastive learning objective to enable robust and effective 3D learning from dense regional language supervision. We carry out extensive experiments on ScanNet ScanNet200 and nuScenes datasets and our model outperforms prior 3D open-world scene understanding approaches by an average of 17.2% and 9.1% for semantic and instance segmentation respectively while maintaining greater scalability and lower resource demands. Furthermore our method has the flexibility to be effortlessly integrated with language models to enable open-ended grounded 3D reasoning without extra task-specific training. Code will be released.