Triangulation Guidelines

The triangulate functions Triangulate Connected All, Triangulate Connected Segments Between, Triangulate Connected Segments Multiple, and Triangulate Connected Segments End all require strings to be organised a certain way to get good consistent results.

Connectivity

In order to achieve good results from these functions, all the segments that need to be triangulated need to be connected together properly. The term connected means that two segments share a common point in space, i.e. they have exactly the same x y and z coordinates. If there are points that are near by, the triangulation function will not perform as expected, and it will produce a self intersecting and generally useless result.

To aid finding points where are near to each other, but not touching, use the STRING CLEAN function, and tell it to mark points that are greater than 0.005 and less than a distance that suits your data. This will highlight any points that are close, but not touching, giving a good indication if there are any badly positioned points.

Another problem related to the point proximity issue, is having line segments intersect, but not having an actual point where they intersect. The applications rely on common points defining how segments connect together. If two segments just cross over each other, the algorithms will not consider the two segments to be connected, and once again, appear to do the wrong thing.

Complexity

Another thing to strive for is to make the input strings and segments as simple as possible. The main rule to follow is to avoid having more than four line segments coming out of a single point. If it means moving some of the connected segments to a nearby point, then that is what should be done. This is especially important when bifurcations are needed. Since it will take a fair amount of extra connecting segments, it is very easy to have more than four lines coming out of a point.