CG_3DArea — Computes area of 3D surface geometries. Will return 0 for solids.
floatCG_3DArea(geometry geom1);
Availability: 3.5.0
            
 Questo metodo richiede il backend SFCGAL. 
            
 Questo metodo implementa la specifica SQL/MM.  SQL-MM IEC 13249-3: 8.1, 10.5
            
 Questa funzione supporta il 3d e non distrugge gli z-index. 
            
 Questa funzione supporta le Polyhedral Surface. 
            
 Questa funzione supporta i Triangoli e le Triangulated Irregular Network Surfaces (TIN). 
Note: By default a PolyhedralSurface built from WKT is a surface geometry, not solid. It therefore has surface area. Once converted to a solid, no area.
SELECT CG_3DArea(geom) As cube_surface_area,
            CG_3DArea(CG_MakeSolid(geom)) As solid_surface_area
            FROM (SELECT 'POLYHEDRALSURFACE( ((0 0 0, 0 0 1, 0 1 1, 0 1 0, 0 0 0)),
            ((0 0 0, 0 1 0, 1 1 0, 1 0 0, 0 0 0)),
            ((0 0 0, 1 0 0, 1 0 1, 0 0 1, 0 0 0)),
            ((1 1 0, 1 1 1, 1 0 1, 1 0 0, 1 1 0)),
            ((0 1 0, 0 1 1, 1 1 1, 1 1 0, 0 1 0)),
            ((0 0 1, 1 0 1, 1 1 1, 0 1 1, 0 0 1)) )'::geometry) As f(geom);
            cube_surface_area | solid_surface_area
            -------------------+--------------------
            6 |                  0