ST_3DArea — 计算三维曲面几何图形的面积。对于实体将返回0。
floatST_3DArea(
geometry geom1)
;
可用性:2.1.0
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).
注意:默认情况下,从WKT构建的多面体曲面是曲面几何图形,而不是实体。因此,它有表面积。一旦转换成实体,就没有面积。
SELECT ST_3DArea(geom) As cube_surface_area, ST_3DArea(ST_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