Navmesh not rebuilding at runtime correctly

Hi,

I’m currently working on a procedurally generated level. All the generation is done on begin play in the level blueprint, after which, the navmesh is rebuilt. However, some of the walkways generated are missed by the nav mesh.

As far as I can tell this is entirely at random. All of the meshes have collision and affect navigation. Even more perplexing is that an instance of a mesh might have the nav mesh generate on it, but another instance of the same mesh won’t have nav mesh on it.

Any ideas?

UPDATE :
So after some messing about with, if I eject from the game, grab the walkway actor (the walkways throughout the level are all static mesh components attached to one actor) and move it a few units out of position it rebuilds the nav mesh redbuilds correctly.

Still don’t have the first clue what the issue is though.

After modifying the ProceduralMeshComponent, do this: UNavigationSystem::UpdateComponentInNavOctree(*MyProceduralMeshComponent);