triangle -D

Conforming Delaunay triangulation: use this switch if you want to ensure that all the triangles in the mesh are Delaunay, and not merely constrained Delaunay; or if you want to ensure that all the Voronoi vertices lie within the triangulation. (Some finite volume methods have this requirement.) This switch invokes Ruppert's original algorithm, which splits every subsegment whose diametral circle is encroached. It usually increases the number of vertices and triangles.