MO-Transformer: A Transformer-Based Multi-Object Point Cloud Reconstruction Network

This paper proposes a new network for reconstructing multi-object point cloud. Different from previous networks which reconstruct multi-object point cloud as a whole, our network iteratively reconstructs each individual object point cloud from a frame of multi-object point cloud. To achieve this goal, we have designed MO-Transformer, a transformer-based autoregressive network. During training, MO-Transformer takes a frame of multi-object point cloud and individual object point clouds as input. During testing, MO-Transformer iteratively reconstructs individual object point clouds only based on the input multi-object point cloud. To train the proposed MO-Transformer, we design a new loss function called separate Chamfer distance (SCD). In addition, we prove that SCD is an upper bound of the traditional Chamfer distance calculated based on the entire multi-object point cloud. The reconstruction experiment verifies the efficacy of our network in multi-object point cloud reconstruction. Furthermore, the reconstruction experiment also investigates the effect of different dimensions using a series of datasets. The ablation study experiment verifies the necessity of SCD in training MO-Transformer.