The irregularity and permutation invariance of point cloud data pose challenges for effective learning. Conventional methods for addressing this issue involve converting raw point clouds to intermediate representations such as 3D voxel grids or range images. While such intermediate representations solve the problem of permutation invariance, they can result in significant loss of information. Approaches that do learn on raw point clouds either have trouble in resolving neighborhood relationships between points or are too complicated in their formulation. In this paper, we propose a novel approach to representing point clouds as a locality preserving 1D ordering induced by the Hilbert space-filling curve. We also introduce Point2Point, a neural architecture that can effectively learn on Hilbert-sorted point clouds. We show that Point2Point shows competitive performance on point cloud segmentation and generation tasks. Finally, we show the performance of Point2Point on Spatio-temporal Occupancy prediction from Point clouds.

本文提出一种利用希尔伯特空间填充曲线作为本地保留的一维排序的方法表示点云，并引入Point2Point神经架构，能够有效地学习排序后的点云并在点云分割和生成任务上展示出有竞争力的性能，最后展示了在点云的时空占用预测上，Point2Point的性能表现。

Point2Point: 一种在希尔伯特排序点云上高效进行深度学习的框架，并在时空占据预测中应用