Beskrivning

Tillgänglighet: 3.5.0

Denna metod behöver SFCGAL-backend.

Denna funktion stöder 3d och kommer inte att tappa z-index.

Denna funktion stöder polyedriska ytor.

Denna funktion stöder trianglar och triangulerade oregelbundna nätverksytor (TIN).

Denna metod implementerar SQL/MM-specifikationen. SQL-MM IEC 13249-3: 9.1 (samma som CG_3DVolume)

Closed surface geometries can have non-zero volume. Use CG_MakeSolid when the geometry value itself must carry the solid flag.

Exempel

A closed polyhedral surface has volume. CG_MakeSolid makes the solid representation explicit.

SELECT CG_Volume(geom) As cube_surface_vol,
    CG_Volume(CG_MakeSolid(geom)) As solid_surface_vol
    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_vol | solid_surface_vol
    ------------------+-------------------
    1 |                 1

Se även

CG_3DArea, CG_MakeSolid, CG_IsSolid