Why won't my NavMesh show when I press P?

My level includes a very large NavMeshBounds Volume, and I have spawning Blueprint static meshes to make up the playable surface. I have added a Navigation Invoker to my player character and I’ve turned on Runtime generation to Dynamic.

When I run the game, I try to view paths by pressing ', followed by num 0. However, the debug menu shows the Navmesh section greyed out (as shown below). (EDIT: I was being an idiot and not viewing through the console command “show navigation”, that works as expected).

114194-navmesh_debug1.png

I can only assume that the NavMesh is not being built. Is this because there’s no NavMesh to show? No geometry exists in the level until runtime, might this be related?

EDIT: I’ve run a test where I’m using static meshes which exist as actors in the level to see if the NavMesh will build on that. Same result.

EDIT2: So I’ve progressed a bit. I can now see my NavMesh generating on static meshes which exist in the level (the EDIT above’s problem). I’m still not seeing it appear on spawned blueprint meshes which is my overall goal. The property in the mesh editor “Is Dynamic Obstacle” appears to be one of the key factors. Turning it on and off allows it to generate Navmesh on the in-world static mesh or not. I read elsewhere that setting the area class to Nav_Area_Obstacle allowed for spawned meshes to be detected, but it’s not what I’m seeing.

I was having the same issue after turning on NAV mesh invokers. You kind of just have to trust that it’s working at this point because it’s not actually going to build your nav mesh unless there’s an Evoker present. Which is usually placed on your AI and your player. Just make sure the volume encompasses your whole level and you’ll be fine.

But if you want to see it again in the viewport, you need to disable invokers set your nav mash generation back to static, then cut and paste your nav mesh volume and it should generate again.