ST_ConstrainedDelaunayTriangles

Name

ST_ConstrainedDelaunayTriangles — Return a constrained Delaunay triangulation around the given input geometry.

Synopsis

geometry ST_ConstrainedDelaunayTriangles ( geometry g1 ) ;

Description

Return a Constrained Delaunay triangulation around the vertices of the input geometry. Output is a TIN.

This method needs SFCGAL backend.

Availability: 3.0.0

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

Examples

ST_ConstrainedDelaunayTriangles of 2 polygons

select ST_ConstrainedDelaunayTriangles(
               ST_Union(
                       'POLYGON((175 150, 20 40, 50 60, 125 100, 175 150))'::geometry,
                       ST_Buffer('POINT(110 170)'::geometry, 20)
                   )
           );
				

ST_DelaunayTriangles of 2 polygons. Triangle edges cross polygon boundaries.

select ST_DelaunayTriangles(
               ST_Union(
                       'POLYGON((175 150, 20 40, 50 60, 125 100, 175 150))'::geometry,
                       ST_Buffer('POINT(110 170)'::geometry, 20)
                   )
	   );