3DSFLabelling: Boosting 3D Scene Flow Estimation by Pseudo Auto-labelling
Authors: Chaokang Jiang, Guangming Wang, Jiuming Liu, Hesheng Wang, Zhuang Ma, Zhenqiang Liu, Zhujin Liang, Yi Shan, Dalong Du

Learning 3D scene flow from LiDAR point clouds presents significant difficulties including poor generalization from synthetic datasets to real scenes scarcity of real-world 3D labels and poor performance on real sparse LiDAR point clouds. We present a novel approach from the perspective of auto-labelling aiming to generate a large number of 3D scene flow pseudo labels for real-world LiDAR point clouds. Specifically we employ the assumption of rigid body motion to simulate potential object-level rigid movements in autonomous driving scenarios. By updating different motion attributes for multiple anchor boxes the rigid motion decomposition is obtained for the whole scene. Furthermore we developed a novel 3D scene flow data augmentation method for global and local motion. By perfectly synthesizing target point clouds based on augmented motion parameters we easily obtain lots of 3D scene flow labels in point clouds highly consistent with real scenarios. On multiple real-world datasets including LiDAR KITTI nuScenes and Argoverse our method outperforms all previous supervised and unsupervised methods without requiring manual labelling. Impressively our method achieves a tenfold reduction in EPE3D metric on the LiDAR KITTI dataset reducing it from 0.190m to a mere 0.008m error.