The LuckGrib WR solver is unique among isochronal solvers in that it can accept a series of constraint points, each of which must be left to port or left to starboard. These constraint sequences are a flexible way for you to describe the shapes of the routes you would like to see.

Constraint sequences can be used in a variety of ways, as discussed in more detail in the Introduction | Constraints page, as well as the Getting Started | Constraints area.