unity-navmesh

name: unity-navmesh description: > Add AI navigation in Unity 6.3 LTS: bake a NavMesh with the AI Navigation package (NavMeshSurface), move agents with NavMeshAgent.SetDestination, and handle dynamic obstacles. Use when setting up pathfinding, making an enemy chase the player, baking navigation, or when the user mentions NavMesh, NavMeshAgent, NavMeshSurface, NavMeshObstacle, or Unity pathfinding.

Unity NavMesh (AI Navigation)

Give NPCs pathfinding in Unity 6.3 LTS: bake walkable surfaces and move agents around obstacles. Targets Unity 6.3 LTS (6000.3) with the AI Navigation package 2.x.

Version trap (Unity 2022+/6): the old built-in Navigation window (Object/Bake tabs) is gone. Baking is now component-based via the AI Navigation package (com.unity.ai.navigation): add a NavMeshSurface to your level geometry and click Bake. The runtime NavMeshAgent/NavMesh API stays in built-in UnityEngine.AI.

When to use

• Use when an agent needs to walk/chase/patrol to a target, when baking a navigable surface, adding dynamic blockers (NavMeshObstacle), or checking whether a destination is reachable.
• Use when the project has the AI Navigation package, a NavMeshSurface component, or scripts using UnityEngine.AI.NavMeshAgent.

When not to use: the decision logic of when/where to move (FSMs, behaviour trees, steering) → game-ai (this skill is the Unity movement/pathing mechanism). Force-driven or kinematic movement that isn't pathfinding → unity-physics.

Core workflow

1. Install the AI Navigation package (Package Manager → com.unity.ai.navigation).
2. Bake a surface: select the static level geometry, Add Component → Navigation → NavMesh Surface, set the agent type/area settings, and click Bake. Re-bake whenever geometry, NavMeshModifiers, or agent settings change.
3. Add a NavMeshAgent to each moving NPC; its radius/height/speed must match the baked agent type, and it must spawn on the baked mesh.
4. Drive it from script with SetDestination(targetPos); the agent steers and avoids other agents automatically. Detect arrival with remainingDistance/pathPending.
5. Handle dynamic blockers with NavMeshObstacle (carving) so closed doors/crates block paths without a full re-bake.
6. Verify with the AI Navigation overlay (the baked mesh is drawn in the Scene view) and by watching agents path around obstacles to the goal; check NavMeshPath.status for unreachable targets.

Patterns

1. Chase/seek with a NavMeshAgent

using UnityEngine;
using UnityEngine.AI;

[RequireComponent(typeof(NavMeshAgent))]
public class Chaser : MonoBehaviour
{
    [SerializeField] private Transform target;
    private NavMeshAgent _agent;

    private void Awake() => _agent = GetComponent<NavMeshAgent>();

    private void Update()
    {
        if (target) _agent.SetDestination(target.position);   // re-path toward the target
    }

    // 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 OffMeshLinks.
• 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.