unity-navmesh Checked

// Arrived? pathPending guards the first frame before a path exists.

private bool HasArrived() =>

!_agent.pathPending && _agent.remainingDistance <= _agent.stoppingDistance;

}

### 2. Check reachability before committing

using UnityEngine.AI;

public bool CanReach(NavMeshAgent agent, Vector3 destination)

{

var path = new NavMeshPath();

agent.CalculatePath(destination, path);

return path.status == NavMeshPathStatus.PathComplete; // vs Partial / Invalid

}

### 3. Bake at runtime (for procedurally built or streamed levels)

using Unity.AI.Navigation; // the package namespace (NavMeshSurface)

[SerializeField] private NavMeshSurface surface;

// After spawning level geometry, build the navmesh in code.

public void RebuildNav() => surface.BuildNavMesh();

### 4. Dynamic obstacle that carves the mesh

// Add a NavMeshObstacle (Carve = true) to a door/crate. While present it cuts a hole in the

// navmesh so agents route around it; remove/disable it to reopen the path — no re-bake needed.

### 5. Connect separate mesh pieces with a NavMeshLink (jumps, doors, gaps)

// Two baked surfaces that don't touch (a ledge and the floor below, two platforms across a

// gap) are separate islands — an agent can't path between them. Add Component > Navigation >

// NavMesh Link to bridge them: assign Start/End Transforms, set Width (0 = point-to-point),

// and toggle Bidirectional for one-way vs two-way. NavMeshLink lives in Unity.AI.Navigation.

// It replaces the deprecated built-in OffMeshLink (see pitfalls).

## Pitfalls

- **Looking for the Navigation window** — it no longer exists in Unity 6. Use the AI Navigation
  package's `NavMeshSurface` component + Bake.
- **Agent doesn't move / warps to origin** — it isn't on the baked mesh, or no surface was
  baked. Bake the surface and spawn the agent on it (`NavMesh.SamplePosition` to snap).
- **Agent ignores new geometry** — the navmesh is baked; runtime-spawned obstacles need a
  `NavMeshObstacle` (carving) or a `surface.BuildNavMesh()` re-bake.
- **`SetDestination` every frame is wasteful** — for a slow-moving target, re-path on a timer
  (e.g. every 0.2s) instead of each frame.
- **Agent radius/height mismatch** — if the `NavMeshAgent`'s size differs from the baked agent
  type, it gets stuck in gaps or floats; keep them consistent.
- **Agents jitter against each other** — tune `avoidancePriority` and quality, or use an
  obstacle for truly static blockers rather than relying on agent avoidance.
- **Reaching for `OffMeshLink`** — the built-in `OffMeshLink` component is **deprecated** in
  AI Navigation 2.0 and can no longer be added from the Add Component menu. Use a
  **`NavMeshLink`** (from the package, `Unity.AI.Navigation`) instead — it adds Transform-based
  endpoints and a runtime `activated` property. Migrate any existing `OffMeshLink`s.
- **`CalculatePath` returns `PathPartial`** — the destination sits on a *different* baked
  island than the agent (a gap the mesh doesn't cross). Bridge the two with a `NavMeshLink`
  (pattern 5) or extend the geometry so one surface covers both; a partial path only reaches
  the near edge.

## References

- Primary docs: AI Navigation package manual
  (`https://docs.unity3d.com/Packages/com.unity.ai.navigation@2.0/manual/index.html`),
  the `NavMeshLink` page
  (`https://docs.unity3d.com/Packages/com.unity.ai.navigation@2.0/manual/NavMeshLink.html`)
  and its "What's new" note on the `OffMeshLink` deprecation
  (`https://docs.unity3d.com/Packages/com.unity.ai.navigation@2.0/manual/whats-new.html`), plus
  `ScriptReference/AI.NavMeshAgent`, `ScriptReference/AI.NavMesh`.

## Related skills

- `game-ai` — engine-agnostic decision-making (FSM, behaviour trees, steering) that *uses* this.
- `unity-csharp-scripting` — the MonoBehaviour structure around the agent.
- `tower-defense` / `fps-shooter` — genres that compose pathfinding with gameplay.