Xu, Mingye, Zhipeng Zhou, Junhao Zhang, and Yu Qiao. 2021. “Investigate Indistinguishable Points in Semantic Segmentation of 3D Point Cloud”. Proceedings of the AAAI Conference on Artificial Intelligence 35 (4):3047-55. https://ojs.aaai.org/index.php/AAAI/article/view/16413.