Mesh  

mass_properties

GiD_Tools mesh mass_properties <tetrahedra_ids> | -boundary_elements <triangle_ids>
To calculate the mass properties of volume, gravity center and inertia tensor of a volume, defined by a selection of tetrahedra or the selection of the triangles bounding the volume.
<tetrahedra_ids> A list of integer ids of the tetrahedra of the volume to be computed
<triangle_ids> A list of integer ids of the triangles that enclose a volume, with normals pointing inside.

It returns a list with 3 items: mass {center_x center_y center_z} {Ixx Iyy Izz Ixy Iyz Ixz}
the 6 inertia values describe the symmetric 3x3 inertia tensor

Ixx Ixy Ixz
Ixy Iyy Iyz
Ixz Iyz Izz

Note: this command is similar to GiD_Info listmassproperties, but this command is not computing inertias

intersectvolumeslines

GiD_Tools mesh intersectvolumeslines <group_lines>
Specialized command that calculate the intersections of the line elements that belong to the group named <group_lines> with the current mesh of hexahedra.