Previous top-performing approaches for point cloud instance segmentation involve a bottom-up strategy, which often includes inefficient operations or complex pipelines, such as grouping over-segmented components, introducing additional steps for refining, or designing complicated loss functions. The inevitable variation in the instance scales can lead bottom-up methods to become particularly sensitive to hyper-parameter values. To this end, we propose instead a dynamic, proposal-free, data-driven approach that generates the appropriate convolution kernels to apply in response to the nature of the instances. To make the kernels discriminative, we explore a large context by gathering homogeneous points that share identical semantic categories and have close votes for the geometric centroids. Instances are then decoded by several simple convolutional layers. Due to the limited receptive field introduced by the sparse convolution, a small light-weight transformer is also devised to capture the long-range dependencies and high-level interactions among point samples. The proposed method achieves promising results on both ScanetNetV2 and S3DIS, and this performance is robust to the particular hyper-parameter values chosen. It also improves inference speed by more than 25% over the current state-of-the-art. Code is available at: https://git.io/DyCo3D

研究了点云（point cloud）语义实例分割的问题，提出了一种动态的、无需生成建议、数据驱动的方法，可以根据实例的特点生成适当的卷积核，在几个简单的卷积层中解码实例，并采用小型轻量级Transformer来捕捉点样本之间的长距依赖和高级别交互。该方法在ScanetNetV2和S3DIS数据集上均取得了良好的结果，在超参数选择上具有鲁棒性，并且比最先进的方法可提高25%以上的推理速度。

DyCo3D：通过动态卷积实现稳健的三维点云实例分割