ST_DelaunayTriangles-ApsaraDB RDS(RDS)-阿里云帮助中心

Returns the Delaunay triangulation computed around the vertices of the input geometry object.

Syntax

geometry ST_DelaunayTriangles(geometry g1, float tolerance, int4 flags);

Parameters

Parameter	Description
`g1`	The input geometry object.
`tolerance`	The snapping tolerance applied to the vertices of the input geometry object.
`flags`	Controls the output geometry type. Valid values: `0` (default), `1`, `2`.

flags values

Value	Output
`0`	A collection of polygon objects. This is the default value.
`1`	A `MultiLineString` object.
`2`	A triangulated irregular network (TIN) surface.

Description

ST_DelaunayTriangles supports triangles and triangulated irregular network (TIN) surfaces as output geometry types.

Examples

The following example runs ST_DelaunayTriangles with default parameter settings, using a set of random points generated within a unit square polygon.

select g,ST_DelaunayTriangles(g) from (select ST_GeneratePoints('POLYGON((0 0,1 0,1 1,0 1,0 0))'::geometry,30) as g) as t;