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ST_Extrude

Signatures

GEOMETRYCOLLECTION ST_Extrude(GEOMETRY geom, DOUBLE height);
GEOMETRYCOLLECTION ST_Extrude(GEOMETRY geom, DOUBLE height,
                              INT flag);

Description

Extrudes geom by height, returning a GEOMETRYCOLLECTION containing the floor (geom), the walls and the roof.

To extract walls, set flag=1; to extract the roof, set flag=2.

Examples

SELECT ST_Extrude('LINESTRING(1 1, 4 4)', 5);
-- Answer: GEOMETRYCOLLECTION(
--    (floor)      LINESTRING(1 1 0, 4 4 0),
--    (wall)       MULTIPOLYGON(((1 1 0, 1 1 5, 4 4 5,
--                                4 4 0, 1 1 0))),
--    (roof)       LINESTRING(1 1 5, 4 4 5))

SELECT ST_Extrude('POLYGON((0 0, 3 0, 3 3, 0 3, 0 0))', 5);
-- Answer: GEOMETRYCOLLECTION(
--             POLYGON((0 0 0, 0 3 0, 3 3 0, 3 0 0, 0 0 0)),
--             MULTIPOLYGON(((0 0 0, 0 0 5, 0 3 5, 0 3 0, 0 0 0)),
--                          ((0 3 0, 0 3 5, 3 3 5, 3 3 0, 0 3 0)),
--                          ((3 3 0, 3 3 5, 3 0 5, 3 0 0, 3 3 0)),
--                          ((3 0 0, 3 0 5, 0 0 5, 0 0 0, 3 0 0))),
--             POLYGON((0 0 5, 3 0 5, 3 3 5, 0 3 5, 0 0 5)))

POLYGON with hole:
SELECT ST_Extrude('POLYGON((0 10, 10 10, 10 0, 0 0, 0 10),
                      (1 3, 3 3, 3 1, 1 1, 1 3))', 10);
-- Answer: GEOMETRYCOLLECTION(
--             POLYGON((0 10 0, 10 10 0, 10 0 0, 0 0 0,
--                       0 10 0),
--                      (1 3, 1 1, 3 1, 3 3, 1 3)),
--             MULTIPOLYGON(((0 10 0, 0 10 10, 10 10 10,
--                            10 10 0, 0 10 0)),
--                          ((10 10 0, 10 10 10, 10 0 10,
--                            10 0 0, 10 10 0)),
--                          ((10 0 0, 10 0 10, 0 0 10,
--                            0 0 0, 10 0 0)),
--                          ((0 0 0, 0 0 10, 0 10 10,
--                            0 10 0, 0 0 0)),
--                          ((1 3 0, 1 3 10, 1 1 10, 1 1 0,
--                            1 3 0)),
--                          ((1 1 0, 1 1 10, 3 1 10, 3 1 0,
--                            1 1 0)),
--                          ((3 1 0, 3 1 10, 3 3 10, 3 3 0,
--                            3 1 0)),
--                          ((3 3 0, 3 3 10, 1 3 10,
--                            1 3 0, 3 3 0))),
--             POLYGON((0 10 10, 0 0 10, 10 0 10, 10 10 10, 0 10 10),
--                (1 3 10, 3 3 10, 3 1 10, 1 1 10, 1 3 10))))
ST_Extrude with flag parameter:
SELECT ST_Extrude('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))', 10, 1);
-- Answer: MULTIPOLYGON(((0 0 0, 0 0 10, 0 1 10, 0 1 0, 0 0 0)),
--            ((0 1 0, 0 1 10, 1 1 0, 1 1 10, 0 1 0)),
--            ((1 1 0, 1 1 10, 1 0 10, 1 0 0, 1 1 0)),
--            ((1 0 0, 1 0 10, 0 0 10, 0 0 0, 1 0 0))))

SELECT ST_Extrude('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))', 10, 2);
-- Answer: POLYGON((0 0 10, 1 0 10, 1 1 10, 0 1 10, 0 0 10))
See also