Got it, thanks a million! But I just got in some new troubles lol. I created a mesh file namely ‘test_mouse.mesh’. I was able to load it, but when I do “domain = FEDomain(‘domain’, mesh)”, a warning occurs: bad element orientation, trying to correct, … corrected. But still I could use this domain to create regions, and resview showed the regions were just as expected. So what does this warning mean, does SfePy requires special vertices indexing? And what happened when “trying to correct“, did it change my previous vertices and/or tetrahedra indexing?

I have attached the mesh file, could please check what is wrong with my mesh? Thanks a lot!