Hi, This isn't something that we have a tool for in FSL. I'm not sure why you would need it though. All the best, Mark On 16 Nov 2013, at 14:54, Rujing Zha <[log in to unmask]<mailto:[log in to unmask]>> wrote: Dear all, May I ask a question about how to get a centre-of-gravity of a mesh surface? Did I realize it only by fslview or some other convenient tools? Thanks. All the best. Rujing Zha