“…These methods exploit descriptors representing the surface in the proximity of a vertex, like the bag of features based approach of [16], the 3D Shape Spectrum Descriptor used within the MPEG-7 framework or the spin-image descriptor, firstly introduced in [3] for object matching and then used for 3D retrieval in the schemes of [17] and [18]. There are also methods that combine both local and global descriptors, e.g., in [19] the global 3D shape is represented by the spatial configuration of a set of specific local shapes.…”