I am working on a procedurally generated dungeon for my university assignment. In 4.6 the navmesh worked on anything that was created during runtime but after switching to 4.7 the navmesh isn’t built on anything that is created during play.
How can I fix this? I assume the issue is that it isn’t being built at runtime but I could be wrong. Any help would be greatly appreciated.
Could use some more info about your setup. Can you double-check your navigation properties in Project Settings? Also, are you using BSPs? Any additional details will be helpful.
–mieszko
I’m using InstancedStaticMeshes. Everything is ticked for rebuilding, both on the abstract, recast and navmesh; I have tried registering the components in code during their construction but with no luck.
In this image you can see that the navigation is not being built inside the rooms, the boxes are collisions for the generation.
I’m also having this issue just spawning Blueprints with meshes in them. It has been working up until 4.7.
I’m spawning StaticMeshes but only near the origin of the map does it build “some” navmesh, but it just keeps rebuilding “some” small portion of it. Seems to be at random.
Is rebuilding navmesh at runtime broken completely right now?
No, we use it all the time and it is not broken. We fixed a number of issues under the hood and its possible that your BPs worked by change. I need more details to be able to tell what’s wrong. Specifically make sure all relevant parts are marked as Can Ever Affect Navigation and have pawn or vehicle collision enabled.
Instanced static meshes are a special case. I need to repro it and I’ll get back to you.
Not sure what the problem is then. Maybe I can provide enough info here to get in me in right direction.
This is what I get when after starting. It keeps rebuilding a small area.
This is what it looks like after 3min or so.
It build navmesh fine without doing it at runtime though.
So If I move one after the game starts, it builds the navmesh properly. But still not doing anything by itself.
This is the exact same issue I’m having; with the same settings.
Found the problem. The navigation system heading in the project settings was overwriting the settings that I had changed in the level itself. I corrected them, saved and then added the navigation system back into the level and it now builds correctly.
Yeah, that’s a kind of a “feature” that’s on our list of things to improve. Sorry! And keep on rocking! 
Thanks for the help Mieszko; appreciate it
What exactly did you end up doing? I’m unable to find “navigation system heading in the project settings.” 
Thanks!
Go to Settings (Next to Marketplace) Then general > Navigation Mesh / Settings and then tick rebuild at runtime.
Thanks, I had “Build on Runtime” checked but not “Force Rebuild on Load”. That fixed it.
Thanks for leading me to the right place.
I am having the same problem but force rebuild on load seems to make things worse. Also, the comment for “Force Rebuild on Load” seems backwards in 4.7. Is it correct?
Finally, is this issue fixed in UE 4.9 or does epic plan to fix it soon?
Thanks,
-X
wow this drove me crazy for hours before finding that the project settings are overriding the in-level setting…
It would be nice to at least write it in the tooltip!
