“…Rich surface and hidden geometric/graph structure amply depict the discrepancy among shapes. The shape descriptors mentioned in [51] are practical in retrieval for polygon meshes and point clouds, e.g., global information [32], local features [11,43,39,12], Zernike moment [30], distribution [33,27], skeleton [37], topology [3,41]. Recently, deep learning methods for 3D shape retrieval based on shape structure have been proposed.…”