GP-NeRF: Generalized Perception NeRF for Context-Aware 3D Scene Understanding
Authors: Hao Li, Dingwen Zhang, Yalun Dai, Nian Liu, Lechao Cheng, Jingfeng Li, Jingdong Wang, Junwei Han

Applying Neural Radiance Fields (NeRF) to downstream perception tasks for scene understanding and representation is becoming increasingly popular. Most existing methods treat semantic prediction as an additional rendering task i.e. the "label rendering" task to build semantic NeRFs. However by rendering semantic/instance labels per pixel without considering the contextual information of the rendered image these methods usually suffer from unclear boundary segmentation and abnormal segmentation of pixels within an object. To solve this problem we propose Generalized Perception NeRF (GP-NeRF) a novel pipeline that makes the widely used segmentation model and NeRF work compatibly under a unified framework for facilitating context-aware 3D scene perception. To accomplish this goal we introduce transformers to aggregate radiance as well as semantic embedding fields jointly for novel views and facilitate the joint volumetric rendering of both fields. In addition we propose two self-distillation mechanisms i.e. the Semantic Distill Loss and the Depth-Guided Semantic Distill Loss to enhance the discrimination and quality of the semantic field and the maintenance of geometric consistency. In evaluation as shown in Fig. 1 we conduct experimental comparisons under two perception tasks (i.e. semantic and instance segmentation) using both synthetic and real-world datasets. Notably our method outperforms SOTA approaches by 6.94% 11.76% and 8.47% on generalized semantic segmentation finetuning semantic segmentation and instance segmentation respectively