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3D Bin Packing

This project is a fork from Enzo Ruiz implementation of 3D Bin Packing available here version py3dbp==1.1.2. Original 3D Bin Packing implementation is based on this paper. The code is based on gedex implementation in Go.

Usage - in script

from py3dbp import Packer, Bin, Item
from py3dbp import execute_packing

bins = load_box_types()                  # load available bin types from JSON file  <-- 'box' should be refactored to 'bins'
items = load_items_types()               # load the items which needs to be packed from JSON file

items_to_fit = create_items(items)       # create objects to be passed to packer
bin_types = create_bins(bins)            # create bin types to which we will pack the items

execute_packing(items_to_fit: List[Item], bin_types: List[Bin])     # do the packing

Usage - API

  1. Run the api script, which will setup an uvicorn session on http://127.0.0.1:8000.
  2. POST to the http://127.0.0.1:8000/packer endpoint in the following JSON format:
curl -X 'POST' \
'http://localhost:8000/packer' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"items": {
"item1": {
  "name": "euro_pallet",
  "quantity": 40,
  "width": 2.625,
  "hight": 5,
  "depth": 3.94,
  "weight": 600
}},
"bins": {
"container1": {
  "name": "40_ft_container",
  "width": 39.5,
  "hight": 7.75,
  "depth": 7.75,
  "max_weight": 20000
}}
}'

Features

  1. Sorting Bins and Items: [bigger_first=False/True | default=True] By default all the bins and items are sorted from the biggest to the smallest, also it can be vice versa, to make the packing in such ordering.

  2. Number of decimals: [number_of_decimals=X] Define the limits of decimals of the inputs and the outputs. By default is 3.

  3. Visualisation of packed bins: visualize_results(best_bins: List[Bin], export_img=False) Plots the items fitted into the bins. [export_img=False/True | default=False] - it is possible to export the visual configuration of each bin to .png file to separate folder: reports.

  4. Textualization of packed bins: textualize_results(best_bins: List[Bin]) Prints to console the packing list as the tree of bins and items packed into each of the bins.

  5. API returning best packed bins in JSON format

Basic Concept

1. Load the bin types and item types

Bin types and items to be fitted are loaded from the JSON files:

  1. load_box_types(file="boxes.json") - will load the bin types that are available to fit the items in. Each bin should be defined in JSON file as below:
{
  "box_type": {
    "name": str,
    "width": float,
    "hight": float,
    "depth": float,
    "max_weight": float
  }
}
  1. load_items_types(file="items.json") - will load the items details that should be fitted into the bins. It is possible to create multiple items of the same type by defining the quatity. Items details should be defined in JSON file as below:
{
  "item_type": {
    "name": str ,
    "quantity": int ,
    "width": float ,
    "hight": float ,
    "depth": float ,
    "weight": float }
}

2. Create Bins and Items objects from the previously loaded JSON files

  • create_bins(bins: dict) -> list

    • will create the list of Bin types objects from previously loaded JSON file.

  • create_items(items: dict) -> list

    • will create the list of Items objects in number specified by quantity parameter in previously loaded JSON file.

  • Bin and Items have the same creation params:

    • my_bin = Bin(name, width, height, depth, max_weight)
my_item = Item(name, width, height, depth, weight)

3. Initialize instance of Packer

  • packer = Packer()              # Packer definition

Methods to be used on packers instance:

  • packer.add_bin(my_bin)         # Adding Bins to packer instance
    • my_bin will be added to packer.bins as one of the types of bins that can be used to pack items.
  • packer.add_item(my_item)       # Adding Items to packer instance
    • my_item will be added to packer.items to be fittedd into the bins
  • packer.remove_item(my_item)    # Removes Item from packer instance
  • packer.pack()                 # Analyze the Items fitting each Bin  - by default (bigger_first=False ~~distribute_items=False,~~ number_of_decimals=3)
    • method tries to fit all Items added to packer to all Bins added to packer. Calling this function will result in each Bin being filled with as many Item as possible. After calling this method each of the Bin in packer instance will hold:
      • my_bin.items - the list of fitted items
      • `my_bin.unfitted_items - the list of items that could not have been fitted into this bin

4. Use execute_packing() function to find the most optimal way of packing all items into available box types.

  • execute_packing(items_to_fit, bin_types, visualize=False, export_img=False, textualize=False)

    • items_to_fit: holds the list of Item type objects
    • bin_types: holds the list of Bin type objects

  • the function workflow is as follow:

    • run the packer.pack() on the initiated items/bins
    • find the bin which was packed in the most effective way (as a % of bin volume utilized by packed items)
    • save this bin and all fitted items to the list of results
    • take all the bins that were not fitted and re-iterate the packer.pack() on those objects
    • do until there are no unfitted items left

Function will return best_packed_bins list.

Credit

License

MIT