The -s switch

• Specifies the maximum number of Steiner points.
• The default is to allow an unlimited number of Steiner points.
• If you specify this switch with no number after it, the limit is set to zero.
• Triangle always adds points at segment intersections, even if it needs to use more points than the limit you set.
• When Triangle creates a conforming Delaunay triangulation, it always adds enough points to ensure that all the segments appear in the triangulation, again ignoring the limit.
• Be forewarned that this switch may result in a conforming triangulation that is not truly Delaunay, because Triangle may be forced to stop adding points when the mesh is in a state where a segment is non-Delaunay and needs to be split. If so, Triangle will print a warning.
• This switch is useful for finding out why Triangle isn't terminating. By forcing Triangle to stop, you can check the intermediate mesh for problem areas.