Nav Mesh doesn't applied to stairs!

This is a house with two floors, and when I tried to set nav mesh to cover floors and stairs, it didn’t work as I imagined.

I have tried to use two nav mesh volumn, but it also did not work.
How can I solve it ?

This is because your agent radius is too big to fit those steps. To solve it use a smaller agent radius, you can set it:

Edit->Project Settings->Navigation Mesh->Agent Radius

or

In your RecastNavMesh-Default actor in your level (generated automatically whenever you place a nav mesh bounding box).

Hope it helps! Is this is the answer you needed make sure to mark this as the correct answers so it helps others find it more easily. Make it a great day!.

I have changed it to a smaller one,but it still don’t work well.

I have changed Agent radius and other parameters in generation settings, and now it works. Thank you, Bariudol.
However,another problem comes. ProjectPointToNavigation funtion in blueprint return a value with false.

Actually, the question I mentioned above is when I change the Agent Radius(Default 35) to other values, it won’t work with ProjectPointToNavigation function.

And I found solution here.link text