Point cloud analysis is a basic task in 3D computer vision, which attracts increasing research attention. Most previous works develop experiments on synthetic datasets where the data is well-aligned. However, the data is prone to being unaligned in the real world, which contains SO3 rotations. In this context, most existing works are ineffective due to the sensitivity of coordinate changes. For this reason, we address the issue of rotation by presenting a combination of global and local representations which are invariant to rotation. Moreover, we integrate the combination into a two-branch network where the highly dimensional features are hierarchically extracted. Compared with previous rotation-invariant works, the proposed representations effectively consider both global and local information. Extensive experiments have demonstrated that our method achieves state-of-the-art performance on the rotation-augmented version of ModelNet40, ShapeNet, and ScanObjectNN (real-world dataset).

本文介绍了一种新的方法来实现点云数据的旋转不变性，使用局部几何特征和全局拓扑特征相结合的局部-全局表示网络。该网络使用多层感知器做注意力机制来融合两种旋转不变性特征，并在模型识别任务上取得了最先进的效果。

旋转不变的点云分类方法：局部几何与全局拓扑相结合