pathfinding3d 0.4.0

Pathfinding algorithms in 3D (based on python-pathfinding)

Pathfinding3D

Pathfinding algorithms for python3 froked from python-pathfinding by @brean.

Currently there are 7 path-finders bundled in this library, namely:

• A*
• Dijkstra
• Best-First
• Bi-directional A*
• Breadth First Search (BFS)
• Iterative Deeping A* (IDA*)
• Minimum Spanning Tree (MSP)

Dijkstra, A* and Bi-directional A* take the weight of the fields on the map into account.

Installation

The package is available on pypi, so you can install it with pip:

pip install pathfinding3d

see pathfinding3d on pypi

Usage examples

For usage examples with detailed descriptions take a look at the examples folder, also take a look at the test/ folder for more examples.

Rerun the algorithm

While running the pathfinding algorithm it might set values on the nodes. Depending on your path finding algorithm things like calculated distances or visited flags might be stored on them. So if you want to run the algorithm in a loop you need to clean the grid first (see Grid.cleanup). Please note that because cleanup looks at all nodes of the grid it might be an operation that can take a bit of time!

Implementation details

All pathfinding algorithms in this library are inheriting the Finder class. It has some common functionality that can be overwritten by the implementation of a path finding algorithm.

The normal process works like this:

1. You call find_path on one of your finder implementations.
2. init_find instantiates the open_list and resets all values and counters.
3. The main loop starts on the open_list. This list gets filled with all nodes that will be processed next (e.g. all current neighbors that are walkable). For this you need to implement check_neighbors in your own finder implementation.
4. For example in A*s implementation of check_neighbors you first want to get the next node closest from the current starting point from the open list. the next_node method in Finder does this by giving you the node with a minimum f-value from the open list, it closes it and removes it from the open_list.
5. if this node is not the end node we go on and get its neighbors by calling find_neighbors. This just calls grid.neighbors for most algorithms.
6. If none of the neighbors are the end node we want to process the neighbors to calculate their distances in process_node
7. process_node calculates the cost f from the start to the current node using the calc_cost method and the cost after calculating h from apply_heuristic.
8. finally process_node updates the open list so find_path can run check_neighbors on it in the next node in the next iteration of the main loop.

flow:

  find_path
    init_find  # (re)set global values and open list
    check_neighbors  # for every node in open list
      next_node  # closest node to start in open list
      find_neighbors  # get neighbors
      process_node  # calculate new cost for neighboring node

Testing

You can run the tests locally using pytest. Take a look at the test-folder

Contributing

Please use the issue tracker to submit bug reports and feature requests. Please use merge requests as described here to add/adapt functionality.

License

python-pathfinding is distributed under the MIT license.

Authors / Contributers

Authors and contributers are listed on github.