In order to rationalize the code of the application, we introduce a new naming policy for variables and functions, based on the underlying concepts. We start from geographical objects, cities and transport networks that we model as graphs, and we finally produce an image made of cones and curves.

Geographical objects |
Mathematical objects |
Graphical objects |

Cities | Nodes of a graph | Cones |

Transport networks | Edges of a graph | Curves |

The geographical objects are modeled in a graph. Producing the end image is a matter of graph drawing which is an identified scientific domain. In order to better distinguish the graph part and the graphical part of the code we emphasize the use of the words *node* and *edges* for the graph and the use of *cones* and *curves* for the graph drawing section. Depending on the choices made by the user, *curves* may be implemented as straight lines, broken segments or Bézier curves.

In the code, the use of the word *line* is restricted to the context of three.js objects.