NavMesh fails with SkeletalMeshActors

I try to use a NavMesh on a level with SkeletalMeshActors and results are not as expected.

SkeletalMeshes are very simple, just like a cabinet with a door. They have a physical asset defined and they aren’t simulating physics. It looks like the NavMesh considers the actor to be rotated of 90° around y; as you can see here if I rotate the actors of 90°, their navmesh area appears like it should be when they aren’t rotated.


Hi Berguina,

I am looking into this and have a few questions. Can you show me what the mesh’s collision looks like in the editor? Also, what is your NavMesh’s settings? A screenshot may help. If you are willing to share one of the assets in quesiton, I can take a look at it myself and see what may be the root cause.


Hi Alexander,

Thank you for looking into this.

Also, what is your NavMesh’s settings?
You find them in the right of the first screenshot ([SUGGESTION] Feature for Blueprint editor - Feedback for Unreal Engine team - Unreal Engine Forums) I’ve linked in previous post.

Here also one of the asset
Let me know if you need any other information or file format.

Sorry about the delay. You are right, the details have been there, I just missed that. I have been attempting this test for a few days, but the Frigo670 asset will not disrupt the navmesh at all.

Skeletal meshes do not disrupt navmesh on their own. I have been trying this using the default character mesh as well, but without a capsule to go with it, the “Can Ever Affect Navigation” has no effect. Have you set these skeletal meshes as part of Blueprints? I can see in your second image that a box collision is present on one mesh, is that part of the skeletal mesh or a Blueprint that it is within?

I use the skeletal mesh inside a BP because I need to spawn and move them at runtime, but the bug can be reproduced also without the BP, just using the skeletal mesh actor.

It’s strange that in your screenshot there isn’t any hole in the navmesh: did you use the physics asset for the mesh? It’s in the same folder.

I can reproduce it like this:

  1. Create a new blank project.
  2. Add a navmesh bounds volume, center at 0,0,0 and size 1000,1000,1000
  3. Enable navmesh drawing
  4. Add my assets to the project, all of them
  5. Drag the skeletalmesh into the center of the map (at 0,0,0). Navmesh is not affected

  1. Pull it a little bit higher at 0,0,20; a hole in the navmesh appears, but not of the expected shape

  1. Rotate the mesh of 90° on the x axis; the hole in the navmesh is now like it should have been in step 6.

I’ve used for the navmesh the default properties with rebuild at runtime enabled.

I use 4.7.2 binary version on windows 7 64bit

Thank you so much for that last post. It took some messing around, but I was able to get it after messing with some properties. I have filed the error into our database (UE-11969), along with a project to show the issue, directly to our lead AI programmer. He is very interested in this one.

Thanks again!