“…With the availability of the existing 3D shape datasets with part annotations [5,3,43], we witness increasing research interests and advances in 3D part-level object understanding. Recently, a variety of learning methods have been proposed to push the state-of-the-art for 3D shape segmentation [29,30,44,17,33,22,7,37,38,40,31,6,24,21]. However, existing datasets only provide part annotations on relatively small numbers of object instances [5], or on coarse yet non-hierarchical part annotations [43], restricting the applications that involves understanding fine-grained and hierarchical shape segmentation.…”