Bad navmesh on static mesh | RESTARTING HELPED

UPDATE: Restarting the editor helped! So this is probably a bug, I’ll move it to Bug Reports…

I have a terrain made in 3D app, it’s a static mesh and its collision is set to per-poly. But when it builds navmesh, it generates way too high and way too inaccurate:

As you can see, it should align with the hills, but it does this instead.
Any clues?


UPDATE: Restarting the editor helped, now it generates correctly - so this must be a bug.

Hello,

  • Have you been able to reproduce this issue in a clean project?
  • Does this issue ever reappear after restarting the editor?
  • Does this issue occur if you use a static mesh that is included with the editor, or only your custom mesh?
  • Have you been able to reproduce this with a different one of your own custom meshes?

No, the issue doesn’t reappear after restarting.
I’ve tried to reproduce it and it seems like the bug appears only when static mesh has per-poly collision. Here are repro steps:


  1. Create a new, blank project without starter content
  2. Enable:

Project Settings → Navigation Mesh → Runtime Generation == Dynamic

Project Settings → Navigation System → Generate Navigation Only Around Navigation Invokers == True


  1. Put the default engine EditorMeshes\AnimTreeEd_Preview static mesh into a scene and scale it to make it bigger (scale == 10.0 on each axis)
  2. Place Nav Mesh Bounds Volume to a level and scale it to make it cover whole level
  3. Enable Show → Navigation to see generated navmesh
  4. Place e.g. a cube on this terrain mesh and add Navigation Invoker Component to it
  5. It will generate navmesh correctly.

  1. Import the provided static mesh, without ‘Auto Generate Collision’
  2. Place it into a level, make sure to cover it with Nav Mesh Bounds Volume
  3. Set its collision to per-poly (Collision Complexity == Use Complex Collision As Simple) and save it
  4. Place e.g. a cube on that terrain mesh and add Navigation Invoker Component to it
  5. It won’t generate the navmesh! <— The bug appears here
  6. Restart the editor. After restarting, the previously placed cube will generate navmesh around it properly.

I’ve included the test mesh to use with repro steps (.zip, to be able to upload it here)TEST MESH

After further investigation, I was able to reproduce your issue. This is currently a known issue, UE-23125, and is being investigated by the developers. Thank you for your report.

Have a great day

Hi there, does this bug still exists in latest version . I am still having issues and have to restart the editor every time I import new geo to the scene.

Thanks

Here is a link so you can keep track of the bug on our public tracker: Unreal Engine Issues and Bug Tracker (UE-23125)