[UE 5.3] NavMesh not generating for specific floor tiles

[Holyfrog848]

Hi all,
I am farily new to UE and i hope the solution here is not too obvious with me being just too blind.
My AI did not move properly after i placed it in some demo environment and i think i finally figured out why. It seems the NavMesh is not being built properly for the floor tiles, only for ground and stairs.

Compared to when i place the SM_Cube:

I already compared it to the SM_Cube of the starter project but cannot see any difference in the Navigation setup and am at a loss now as to why this is happening:
Cube:

Floor:

Can anyone please help me figure this out?

Thank you

[ClockworkOcean]

Does the floor tile mesh actually have collision? Check the simplex collision in the mesh editor, or look at the level in ‘player collision’ mode

[Holyfrog848]

Hi, thank you for your quick reply!

I am not really sure, it looks fine, at least compared to the UE Sample Cube.

However it does not work, so i have to assume something is wrong.
The Player Collision Mode shows this:

Is there a good source to read up on this? I really do not understand what the issue is, when i start and walk around as a player everything is fine, just the AI cannot manage to get a path and the NavMesh shows no green as shown above.

[ClockworkOcean]

There’s your problem

there’s no collision on the floor, I think.

The mesh itself ( in the static mesh editor ) needs to have simplex collision

Or, you can set

[Holyfrog848]

That did indeed fix it for this mesh!

I saw this was set to project default, will check if i can set this globally for all meshes as there are still some rambs and other meshes like corners which do not work properly.

Thank you very much!