What’s A*?
A* (A-star) is a search algorithm used to find the shortest path between two points on a grid or graph.
What’s Unity NavMesh?
NavMesh is Unity’s built-in navigation system.
When to Use A* Algorithm
✅ 2D Grid-Based Games: Great for top-down, tile-map games like Pokémon, Fire Emblem
✅ Custom Pathfinding: You need full control over the algorithm or grid
✅ No Unity Engine (Custom Engine): You’re building from scratch
✅ Dynamic or Procedural Worlds: You generate maps at runtime and need custom solutions
✅ Low-poly / Small Worlds: Simple grid = fast A* computation
When NOT to Use A* (Use NavMesh Instead)
🚫 3D Terrain or Complex Geometry: A* doesn’t understand 3D mesh surfaces
🚫 Need Agent Features: No built-in agent radius/height, obstacle avoidance
🚫 Performance Bottlenecks in Large Maps: Grid-based A* gets slow as grid size increases
🚫 Want Auto Pathfinding in Unity: Unity NavMesh does the heavy lifting automatically
When to Use Unity NavMesh
✅ 3D Games (FPS, Adventure): Works out of the box with terrain, stairs, ramps
✅ You’re Using Unity: Built-in, highly optimized, works with Agents and Obstacles
✅ Want Dynamic Pathfinding: NavMesh can update with NavMesh Surface or Carving
✅ Need Agent-Based AI: Handles multiple AI units with different sizes/behavior
When NOT to Use NavMesh (Use A* Instead)
🚫 2D Games: NavMesh is mainly for 3D navigation (2D support is hacky)
🚫 Fully Dynamic Worlds: You can’t rebake NavMesh instantly at runtime
🚫 Custom Game Engines: NavMesh is Unity-specific
🚫 Hex or Irregular Grids: NavMesh doesn’t support custom-shaped tile systems natively
Find my NavMesh Demo Project Here
TL;DR Summary
- Top-down 2D tile game: A*
- 3D Adventure/FPS: NavMesh
- Procedural dungeons: A*
- RTS / MOBA (3D with units): NavMesh
- Custom logic / AI testing: A*
- Unity 3D project with terrain: NavMesh
How do I handle dynamic environments in a 3D game where the NavMesh must update instantly at runtime?
Unity’s built-in NavMesh system is not ideal for highly dynamic environments. But there are workarounds & better solutions depending on your game’s needs.
Why NavMesh is Limited in Dynamic Worlds
Unity’s NavMesh baking is not real-time. It takes time and can’t rebake every frame. Even NavMeshObstacle with carving only supports:
- Simple object avoidance
- No large-scale changes (like terrain deformation or new platforms appearing)
So if your game has:
- Platforms moving
- Terrain changing
- Buildings spawning/despawning
You need more flexible solutions….
Best Solutions for Real-Time Navigation in Dynamic 3D Worlds
✅ Use NavMesh with Carving enabled for minor changes like doors, crates, small obstacles
✅ Use NavMeshComponents package, when only parts of the environment change
✅ A Pathfinding Project (by Aron Granberg)*
- Best for fully dynamic 3D worlds
- Supports grid, navmesh, and point graph types
- Real-time updates & graph recalculations
- Unity compatible and production-ready
Why it rocks:
- Real-time updates
- Supports layered worlds, moving platforms
- Optimised & widely used in indie and AAA
Find Aron Granberg’s path finding projects:
Free
Paid
Many devs switch to this when Unity’s NavMesh isn’t enough.
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