This is a paid asset, but now you can download AStar 2D Tile Based Pathfinding for FREE, but please remember this package is provided only for learning purposes or to be able to test before buying the product, NOT FOR COMMERCIAL PURPOSES.
Detail this asset from Unity Store: Original Link
AStar 2D Tile Based Pathfinding v1.2.3 (Latest version)
AStar 2D is a complete pathfinding solution for 2D tile or grid based Unity games. It is ideally suited to top down tile based games and tower defense games but can easily be adapted to work in other scenarios.
Features
– Quick and easy setup / integration into existing projects
– Includes easily expandable agent class for path following
-Support for dynamic obstacles using 2D colliders
-Supports node weightings to influence paths based on a penalty value
– Dynamic route updates for changing environments
– Supports any number of search grids
– Assign different grids to different agents to reduce the search space
– Enable / disable diagonal movements in the click of a mouse
– Offload the expensive pathfinding calculations to separate threads to maintain maximum performance (All done behind the scenes, works out of the box)
– Includes visualization tools to help with debugging and analyzing performance
– Includes example scenes and stress tests
– All scripts use custom namespaces to prevent clashing type names
– Comprehensive .chm documentation of the API for quick and easy reference
– Fully commented C# source code included