unity-navmesh

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(

2. Check reachability before committing

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

4. Dynamic obstacle that carves the mesh

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.

References

• Primary docs: AI Navigation package manual (https://docs.unity3d.com/Packages/com.unity.ai.navigation@2.0/manual/index.html) and 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.