ST_Volume
Name
ST_Volume — Computes the volume of a 3D solid. If applied to surface (even closed) geometries will return 0.
Synopsis
float
ST_Volume
(
geometry
geom1
)
;
Description
Availability: 2.2.0
This method needs SFCGAL backend.
This function supports 3d and will not drop the z-index.
This function supports Polyhedral surfaces.
This function supports Triangles and Triangulated Irregular Network Surfaces (TIN).
This method implements the SQL/MM specification. SQL-MM IEC 13249-3: 9.1 (same as ST_3DVolume)
Example
When closed surfaces are created with WKT, they are treated as areal rather than solid. To make them solid, you need to use ST_MakeSolid . Areal geometries have no volume. Here is an example to demonstrate.
SELECT ST_Volume(geom) As cube_surface_vol, ST_Volume(ST_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 ------------------+------------------- 0 | 1