BEVNeXt: Reviving Dense BEV Frameworks for 3D Object Detection
Authors: Zhenxin Li, Shiyi Lan, Jose M. Alvarez, Zuxuan Wu

Recently the rise of query-based Transformer decoders is reshaping camera-based 3D object detection. These query-based decoders are surpassing the traditional dense BEV (Bird's Eye View)-based methods. However we argue that dense BEV frameworks remain important due to their outstanding abilities in depth estimation and object localization depicting 3D scenes accurately and comprehensively. This paper aims to address the drawbacks of the existing dense BEV-based 3D object detectors by introducing our proposed enhanced components including a CRF-modulated depth estimation module enforcing object-level consistencies a long-term temporal aggregation module with extended receptive fields and a two-stage object decoder combining perspective techniques with CRF-modulated depth embedding. These enhancements lead to a "modernized" dense BEV framework dubbed BEVNeXt. On the nuScenes benchmark BEVNeXt outperforms both BEV-based and query-based frameworks under various settings achieving a state-of-the-art result of 64.2 NDS on the nuScenes test set.