Dynamic NavMesh Creation at Runtime?

I googled the topic, but only found posts from before Unity 5, so I have to ask here. Can I procedurally generate an environment and then create a navmesh for it? Or if I can’t: Is it possible to have small modular navmeshes that are bound to small modules of the environment and then simply place them randomly? Would they even be connected?..

You can’T do this with Unity’s built-in navmesh system, but you can use, for example, Aron Granberg’s Astar Pathfinding Project which lets you assign any mesh to a navmesh graph at runtime.