説明

ジオメトリ型について、二つのジオメトリの、3次元の最小デカルト距離 (空間参照系に基づきます)を、投影法の単位で返します。

This function supports 3d and will not drop the z-index.

This function supports Polyhedral surfaces.

This method implements the SQL/MM specification. SQL-MM ?

This method is also provided by SFCGAL backend.

Availability: 2.0.0

Changed: 2.2.0 - In case of 2D and 3D, Z is no longer assumed to be 0 for missing Z.

例

-- ジオメトリの例 - メートル単位(SRID: 2163 米国ナショナルアトラス正積図法)
-- (3次元ポイントとラインの距離と、2次元ポイントとラインの距離とを比較)
-- ご注意: 現在は垂直データムに対応していないので、
-- Zは変換されずに、最終的に同じであると仮定されます。
SELECT ST_3DDistance(
                        ST_Transform(ST_GeomFromEWKT('SRID=4326;POINT(-72.1235 42.3521 4)'),2163),
                        ST_Transform(ST_GeomFromEWKT('SRID=4326;LINESTRING(-72.1260 42.45 15, -72.123 42.1546 20)'),2163)
                ) As dist_3d,
                ST_Distance(
                        ST_Transform(ST_GeomFromText('POINT(-72.1235 42.3521)',4326),2163),
                        ST_Transform(ST_GeomFromText('LINESTRING(-72.1260 42.45, -72.123 42.1546)', 4326),2163)
                ) As dist_2d;

     dist_3d      |     dist_2d
------------------+-----------------
 127.295059324629 | 126.66425605671

-- Multilinestring and polygon both 3d and 2d distance
-- Same example as 3D closest point example
SELECT ST_3DDistance(poly, mline) As dist3d,
    ST_Distance(poly, mline) As dist2d
        FROM (SELECT  ST_GeomFromEWKT('POLYGON((175 150 5, 20 40 5, 35 45 5, 50 60 5, 100 100 5, 175 150 5))') As poly,
                ST_GeomFromEWKT('MULTILINESTRING((175 155 2, 20 40 20, 50 60 -2, 125 100 1, 175 155 1),
                (1 10 2, 5 20 1))') As mline ) As foo;
      dist3d       | dist2d
-------------------+--------
 0.716635696066337 |      0

関連情報

ST_Distance, ST_3DClosestPoint, ST_3DDWithin, ST_3DMaxDistance, ST_3DShortestLine, ST_Transform