Opened 2 years ago

Closed 2 years ago

Last modified 2 years ago

#5162 closed enhancement (fixed)

Expose GEOSConstrainedDelaunayTriangulation as ST_TriangulatePolygon

Reported by: mdavis Owned by: pramsey
Priority: medium Milestone: PostGIS 3.3.0
Component: postgis Version: master
Keywords: Cc:


GEOS 3.11 has added GEOSConstrainedDelaunayTriangulation to provide Constrained Delaunay Triangulation for polygonal geometry.

How should this be exposed? Existing functions which are similar are both backed by SFGCAL: ST_Tesselate and ST_ConstrainedDelaunayTriangles. However, both of these have some additional functionality which isn't in GEOSConstrainedDelaunayTriangulation, and both produce TINs only as output. Design options include:

  • add a new new function for the GEOS functionality. Perhaps ST_Triangulate or ST_TriangulatePolygon. This could output either a Polygon collection or a TIN or both (see switch on ST_DelaunayTriangles).
  • add a branch to ST_Tesselate to use GEOS for polygonal inputs. This would be moved to be under Geometry Processing in the doc. But would be nice to allow Polygon collection output, which means adding a flag.

Change History (5)

comment:1 by mdavis, 2 years ago

My preference is for a new function ST_Triangulate. That indicates exactly what is computed. ST_Tesselate is less precise (the name is just inherited from SFCGAL, I believe). A net new function avoids any conflict or confusion with the CGAL functions.

comment:2 by robe, 2 years ago

Version: 3.2.xmaster

comment:3 by robe, 2 years ago

I'm fine with ST_Triangulate as a name.

comment:4 by robe, 2 years ago

Resolution: fixed
Status: newclosed

I think we settled on ST_TriangulatePolygon -

comment:5 by robe, 2 years ago

Summary: Expose GEOSConstrainedDelaunayTriangulationExpose GEOSConstrainedDelaunayTriangulation as ST_TriangulatePolygon
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