NavMesh Agent ignoring Obstacle Avoidance Radius

Unity Engine
, , ,
1

To preface this question, I am very new to Unity and maybe was just searching for the wrong things but could not seem to find an answer for this.

Have been working on a very small game, and was looking to get a basic AI that navigates some patrol points within a house.

Started by creating a NavMeshSurface and baking afterwards with these Navigation settings

image
image1920×869 116 KB

I went with .1 as the Radius because it looked as if it had the most accurate boundaries.

In that screenshot you can also see how I setup my NavMeshAgent. Apologies for the cluttered picture, but the forums appear to only let me upload one image on a post because I am new.

So from my very limited understanding, I assumed that if I set the Obstacle Avoidance → Radius to the general shape of the AI, then it would keep that cyclindrical avoidance shape within the boundaries of the NavMesh.

But what’s happening is it appears to be allowing that avoidance radius to go outside the mesh surface which causes parts of the zombie to clip through walls.

I am guessing that I am misusing/misunderstanding how the radius on the Navigation window and the radius on the NavMesh agent work.

Seems like I could just raise the radius in the Navigation window which causes the path to be more center through doorways and prevent clipping. But was curious why what I am doing does not work?

2

Interesting your screenshot just labels that field as “Radius:”… I guess they changed that, but you are after all on the Agent tab (at the top).

Older docs still say “Agent Radius:”, which helps infer that you are making a mesh that is tailored to the radius of an agent.

Random doc find, quite out of date I guess:

Screenshot 2025-05-09 at 3.46.07 PM
Screenshot 2025-05-09 at 3.46.07 PM586×860 68 KB

In the old days there was One Navmesh To Nav Them All but now you can have more than one so I suppose if you had agents with wildly-different radii, you’d bake more than one navmesh for each class of agent.

Computationally I am sure it is cheesy-easy to see if a point is within polygons, whereas it would be harder to check a circle.

3

Of course right after I create this, I find this other post

Think this might be what I am looking for? It looks like I misunderstood what the NavMeshAgent radius setting does and what the Navigation radius setting does.

I assumed that the NavMeshAgent radius would respect the boundaries of the mesh surface but looks like that might only be the case for other objects using NavMeshAgent?

I think in order to get rid of the clipping I am seeing, seems like I would just need to tinker with the radius in the Navigation window