Scene Reconstruction as Mapping Priors for 3D Detection

In autonomous driving, mapping is critical for motion planning but remains an under-utilized resource for perception tasks like 3D object detection. Maps can provide robust structural priors of the static environment, suited to resolving ambiguities and correcting for sensor data sparsity or noise — issues especially prevalent for distant objects or during adverse weather conditions. However, conventional High-Definition (HD) maps are resource-intensive to obtain and maintain, which presents a challenge for achieving efficient, large-scale deployment. In this paper, we propose a scalable solution to systemically leverage mapping to improve 3D detection by overcoming two primary challenges. First, we introduce a pipeline to automatically build dense mapping priors from aggregated sensor data, eliminating the need for human labeling. Second, we design a novel Mapping Prior Augmented 3D detection (MPA3D) framework to effectively integrate the mapping priors with the distinct modalities of sensor data. Our extensive experiments on the Waymo Open Dataset demonstrate that our approach achieves new state-of-the-art results, and proving the effectiveness of using scalable, reconstructed scene priors to enhance 3D detection.