# tri_delaunay Join a set of points to make a [Delaunay triangulation](https://en.wikipedia.org/wiki/Delaunay_triangulation). **Since:** 3.0 ## Parameters - `points` : A list of points. - `ret` : The type of returned data. Default to `"TRI_INDICES"` which returns the indices of the `points`. `"TRI_SHAPES"` returns triangle shapes. `"VORONOI_CELLS"` returns voronoi cells. `"DELAUNAY"` returns a delaunay object which can be processed by [`tri_delaunay_indices`](lib3x-tri_delaunay_indices.html), [`tri_delaunay_shapes`](lib3x-tri_delaunay_shapes.html) and [`tri_delaunay_voronoi`](lib3x-tri_delaunay_voronoi.html). ## Examples use use points = [for(i = [0:20]) rands(-100, 100, 2)]; tris = [for(ti = tri_delaunay(points)) [for(i = ti) points[i]]]; linear_extrude(1) for(t = tris) { polygon(t); } color("black") linear_extrude(2) for(t = tri_delaunay(points, ret = "TRI_SHAPES")) { offset(-1) polygon(t); } color("red") linear_extrude(3) for(t = tri_delaunay(points, ret = "VORONOI_CELLS")) { polyline_join([each t, t[0]]) circle(1); } ![tri_delaunay](images/lib3x-tri_delaunay-1.JPG)