A little confused about part_seg and sem_seg?

[elenacliu]

I guess part_seg means part segmentation and sem_seg means semantic segmentation. However what's the difference between them? In my perspective they are the same because in the pointnet++ paper's appendix there's a section named "semantic part segmentation".

[plpplp]

I think difference is that for part segmentation, you try to segment the parts of individual objects while for semantic segmentation, you only try to predict to which object a point belongs to. Can be seen from the original pointnet page.