Multi-level navmeshes

Does the new navmesh system support multi-level navigation? In specific I’m going to use a 2k mesh terrain that has holes in it with a cave system underneath that mesh terrain, all in one scene.

What’s the performance like for a 2k navmesh? Especially with updating it at runtime as things are created/destroyed? I have dynamically placed trees that grow/die/respawn at runtime.

Anyone?

Also wondering if it can handle flying/swimming creatures.

If your creatures don’t need to keep thinking and living when you’re not around, you can have a sliding window navmesh https://github.com/Unity-Technologies/NavMeshComponents/tree/master/Assets/Examples/Scenes
Navmesh is for 2D movement, flying and swimming is better handled with flocking like this https://www.assetstore.unity3d.com/en/#!/content/47393