ST_DELAUNAYTRIANGLES
📄字数 5.1K
👁️阅读量 加载中...
功能描述
计算输入几何体顶点的 Delaunay 三角剖分。
语法格式
sql
GEOMETRY ST_DELAUNAYTRIANGLES(GEOMETRY g1, DOUBLE tolerance = 0.0, INTEGER flags = 0);参数说明
- g1：目标 GEOMETRY 对象；
- tolerance：容差，可用于将附近的输入顶点捕捉在一起，
- flags：结果几何的标志位：
- 0： 三角形 POLYGON 的 GEOMETRYCOLLECTION（默认）
- 1： 三角测量边缘的多线
- 2： 三角测量的 TIN
函数返回类型
GEOMETRY 类型
使用说明
- 该函数是通过GEOS模块实现的。
- 该函数支持 3d 并且不会丢失 z-index。
- 此函数支持三角形和不规则三角网面 (TIN)。
示例
delaunay三角形作为多线串：
sql
SQL> SELECT
ST_AsText(ST_DelaunayTriangles(
ST_Union(ST_GeomFromText('POLYGON((175 150, 20 40,
50 60, 125 100, 175 150))'),
ST_Buffer(ST_GeomFromText('POINT(110 170)'), 20)
),0.001,1))
As dtriag;
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| DTRIAG |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| MULTILINESTRING((121.11140466039204 186.6293922460509,175 150),(117.6536686473018 188.47759065022572,121.11140466039204 186.6293922460509),(113.90180644032256 189.61570560806462,117.6536686473018 188.47759065022572),(110 190,113.90180644032256 189.61570560806462),(106.09819355967743 189.61570560806462,110 190),(102.3463313526982 188.47759065022572,106.09819355967743 189.61570560806462),(98.88859533960796 186.6293922460509,102.3463313526982 188.47759065022572),(95.85786437626905 184.14213562373095,98.88859533960796 186.6293922460509),(93.37060775394909 181.11140466039205,95.85786437626905 184.14213562373095),(91.52240934977426 177.6536686473018,93.37060775394909 181.11140466039205),(20 40,91.52240934977426 177.6536686473018),(20 40,125 100),(125 100,175 150),(124.14213562373095 155.85786437626905,125 100),(124.14213562373095 155.85786437626905,175 150),(124.14213562373095 155.85786437626905,126.62939224605091 158.88859533960795),(126.62939224605091 158.88859533960795,175 150),(126.62939224605091 158.88859533960795,128.47759065022575 162.3463313526982),(128.47759065022575 162.3463313526982,175 150),(128.47759065022575 162.3463313526982,129.61570560806462 166.09819355967744),(129.61570560806462 166.09819355967744,175 150),(129.61570560806462 166.09819355967744,130 170),(130 170,175 150),(129.61570560806462 173.9018064403226,130 170),(129.61570560806462 173.9018064403226,175 150),(128.47759065022572 177.6536686473018,129.61570560806462 173.9018064403226),(128.47759065022572 177.6536686473018,175 150),(126.62939224605091 181.11140466039205,128.47759065022572 177.6536686473018),(126.62939224605091 181.11140466039205,175 150),(124.14213562373095 184.14213562373095,126.62939224605091 181.11140466039205),(124.14213562373095 184.14213562373095,175 150),(121.11140466039204 186.6293922460509,124.14213562373095 184.14213562373095),(117.6536686473018 188.47759065022572,124.14213562373095 184.14213562373095),(124.14213562373095 184.14213562373095,128.47759065022572 177.6536686473018),(117.6536686473018 188.47759065022572,128.47759065022572 177.6536686473018),(102.3463313526982 188.47759065022572,128.47759065022572 177.6536686473018),(102.3463313526982 188.47759065022572,117.6536686473018 188.47759065022572),(102.3463313526982 188.47759065022572,110 190),(110 190,117.6536686473018 188.47759065022572),(110 150,128.47759065022572 177.6536686473018),(102.3463313526982 188.47759065022572,110 150),(95.85786437626905 155.85786437626905,110 150),(95.85786437626905 155.85786437626905,102.3463313526982 188.47759065022572),(90 170,95.85786437626905 155.85786437626905),(90 170,102.3463313526982 188.47759065022572),(90 170,91.52240934977426 177.6536686473018),(91.52240934977426 177.6536686473018,102.3463313526982 188.47759065022572),(91.52240934977426 177.6536686473018,95.85786437626905 184.14213562373095),(95.85786437626905 184.14213562373095,102.3463313526982 188.47759065022572),(90 170,90.38429439193538 173.90180644032256),(90.38429439193538 173.90180644032256,91.52240934977426 177.6536686473018),(20 40,90.38429439193538 173.90180644032256),(20 40,90 170),(90 170,90.38429439193538 166.09819355967744),(20 40,90.38429439193538 166.09819355967744),(50 60,90.38429439193538 166.09819355967744),(20 40,50 60),(50 60,125 100),(50 60,98.88859533960796 153.3706077539491),(98.88859533960796 153.3706077539491,125 100),(98.88859533960796 153.3706077539491,102.3463313526982 151.52240934977425),(102.3463313526982 151.52240934977425,125 100),(102.3463313526982 151.52240934977425,106.09819355967744 150.38429439193538),(106.09819355967744 150.38429439193538,125 100),(106.09819355967744 150.38429439193538,110 150),(110 150,125 100),(110 150,113.90180644032256 150.38429439193538),(113.90180644032256 150.38429439193538,125 100),(113.90180644032256 150.38429439193538,117.6536686473018 151.52240934977425),(117.6536686473018 151.52240934977425,125 100),(117.6536686473018 151.52240934977425,121.11140466039204 153.3706077539491),(121.11140466039204 153.3706077539491,125 100),(121.11140466039204 153.3706077539491,124.14213562373095 155.85786437626905),(110 150,121.11140466039204 153.3706077539491),(110 150,124.14213562373095 155.85786437626905),(113.90180644032256 150.38429439193538,121.11140466039204 153.3706077539491),(98.88859533960796 153.3706077539491,106.09819355967744 150.38429439193538),(98.88859533960796 153.3706077539491,110 150),(95.85786437626905 155.85786437626905,98.88859533960796 153.3706077539491),(50 60,95.85786437626905 155.85786437626905),(50 60,93.37060775394909 158.88859533960795),(93.37060775394909 158.88859533960795,95.85786437626905 155.85786437626905),(91.52240934977426 162.3463313526982,93.37060775394909 158.88859533960795),(91.52240934977426 162.3463313526982,95.85786437626905 155.85786437626905),(90 170,91.52240934977426 162.3463313526982),(90.38429439193538 166.09819355967744,91.52240934977426 162.3463313526982),(50 60,91.52240934977426 162.3463313526982),(124.14213562373095 155.85786437626905,128.47759065022572 177.6536686473018),(128.47759065022572 177.6536686473018,130 170),(124.14213562373095 155.85786437626905,130 170),(124.14213562373095 155.85786437626905,129.61570560806462 166.09819355967744),(126.62939224605091 158.88859533960795,129.61570560806462 166.09819355967744)) |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
(1 row)使用具有Z值的顶点：
sql
SQL> SELECT ST_AsText(ST_DelaunayTriangles(ST_GeomFromText(
'MULTIPOINT Z(14 14 10, 150 14 100,34 6 25, 20 10 150)'))) As wkt;
+-----------------------------------------------------------------------------------------------------------------------------+
| WKT |
+-----------------------------------------------------------------------------------------------------------------------------+
| GEOMETRYCOLLECTION Z (POLYGON Z ((14 14 10,20 10 150,34 6 25,14 14 10)),POLYGON Z ((14 14 10,34 6 25,150 14 100,14 14 10))) |
+-----------------------------------------------------------------------------------------------------------------------------+
(1 row)