The RAIN Navigation system doesn’t (currently) help you with this. We’re not yet supporting off mesh links, so creating a path that goes up a ladder isn’t possible. We’re expecting to add new capabilities to deal with ladders, climbing, jump down points, etc. in version early 2015.
Until then, you could use Navigation Targets or Entity/Aspects to mark locations of climbable ladders. You could add information to pair these locations with the areas they take you to, then have a little bit of logic to help with movement. For example:
1) Let’s say you have 5 ladders that take you up to the top of 5 different buildings. You could place a nav target at the base of each ladder called “Area 1 Up”, “Area 2 Up”, etc. At the top you might have “Area 1 down”, “Area 2 down”, etc.
2) When you know your destination is in “Area 1″, then you would do something like:
— MOVE moveTarget = navigationtarget(“Area 1 up”)
— CUSTOM ACTION -> some code or a mecanim animation to climb the ladder
— MOVE moveTarget = final destination
This definitely requires a little extra work for now, but is doable. Once we get offmesh links in, the pathfinding system will deal with this for you.