LGCPNet : Local-global combined point-based network for shape segmentation

Abstract Segmenting 3D shapes represented by meshes remains a challenging problem, due to the irregularity and complexity of meshes. Point cloud, on the other hand, can be considered as the simplest no-frills approximation for meshes. Therefore, in this paper, we regard the shape segmentation problem as a point labeling task: Given a shape, we first transform it into points encoding barycenters and normal vectors of faces. Then we construct a Barycentric Dual Graph (BDG) on the transformed points, and propose a Barycentric Dual Graph Edge Convolution (BDGEC) to extract features from the graph. Based on the BDGEC, we further propose a novel point-based deep neural network (DNN) named local-global combined point-based network (LGCPNet). Our LGCPNet consists of three modules, of which the Local Module and Global Module capture local and global features respectively, while the Fusion Module uses a gate mechanism to aggregate local features and global features, and obtain the point labeling result. Comprehensive experimental results on various datasets demonstrate that the proposed network inherits the merits of point-based DNNs and achieves the state-of-the-art performance.