I mean that the neighbors to be computed are the crossroads. The roads are created from crossroad to crossroad as links, aren't they? So the points on the shape are crossroads. The segments between points need to follow the road path that connects them, straight or curved, it is not important.


The shape surrounds deadends and always closes itself. Look at this picture:

The only problem is to identify witch shape is the outside, but not really a problem: it is the largest one.


In the moment you have the outside shapes of more than one net, they need to be considered as inside shapes of a global outern shape.



Happy to help... if that helps

I went from theory to practice.

download




Left click to create new cross points. Drag a cross point to another cross point to connect them. Don't try to cross lines without a cross point because it will probably crash... it is just a simple example for proving that the method works

Very nice example txesmi. Thanks for sharing!

Pleased to be useful

I commented the code a bit in order to be more understandable.

Salud!

Nice example, but now try to generate a mesh or a polygon out of all the black areas. Oh and please consider such a network, too



EDIT: This example should result in 2 polygons / meshes.

It is clear that the method is only valid to identify the figures that make up the interstices: a necessary first step to end up doing what you want.