I have used mmg3dls() in order to obtain a mesh divided in sub-domains. I would like to separate the regions in the resulting mesh for saving and have seen that when using mmg2d as an application a simple tag allows to select the sub-domain to export. I have not been able to find anything like this in the 3d version. I have looked into using the MMG3D_Get_tetrahedron() to manually create the mesh file but this becomes a bit cumbersome quite fast since I have not found a way to automatically also get all the corresponding vertices and triangle information for the selected sub-domain. Is there perhaps a build in way to accomplish this like for mmg2d that I have missed? and if not, is there a better way to accomplish this than doing it manually?