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.. _bin_packing:
Bin-Packing Add-on
==================
.. module:: ezdxf.addons.binpacking
This add-on is based on the 3D bin packing module `py3dbp`_ hosted on `PyPI`_.
Both sources of this package are MIT licensed like `ezdxf` itself.
The Bin Packing Problem
-----------------------
Quote from the `Wikipedia`_ article:
The bin packing problem is an optimization problem, in which items of different
sizes must be packed into a finite number of bins or containers, each of a fixed
given capacity, in a way that minimizes the number of bins used.
Example
-------
This code replicates the example used by the `py3dbp`_ package:
.. code-block:: python
from typing import List
import ezdxf
from ezdxf import colors
from ezdxf.addons import binpacking as bp
SMALL_ENVELOPE = ("small-envelope", 11.5, 6.125, 0.25, 10)
LARGE_ENVELOPE = ("large-envelope", 15.0, 12.0, 0.75, 15)
SMALL_BOX = ("small-box", 8.625, 5.375, 1.625, 70.0)
MEDIUM_BOX = ("medium-box", 11.0, 8.5, 5.5, 70.0)
MEDIUM_BOX2 = ("medium-box-2", 13.625, 11.875, 3.375, 70.0)
LARGE_BOX = ("large-box", 12.0, 12.0, 5.5, 70.0)
LARGE_BOX2 = ("large-box-2", 23.6875, 11.75, 3.0, 70.0)
ALL_BINS = [
SMALL_ENVELOPE,
LARGE_ENVELOPE,
SMALL_BOX,
MEDIUM_BOX,
MEDIUM_BOX2,
LARGE_BOX,
LARGE_BOX2,
]
def build_packer():
packer = bp.Packer()
packer.add_item("50g [powder 1]", 3.9370, 1.9685, 1.9685, 1)
packer.add_item("50g [powder 2]", 3.9370, 1.9685, 1.9685, 2)
packer.add_item("50g [powder 3]", 3.9370, 1.9685, 1.9685, 3)
packer.add_item("250g [powder 4]", 7.8740, 3.9370, 1.9685, 4)
packer.add_item("250g [powder 5]", 7.8740, 3.9370, 1.9685, 5)
packer.add_item("250g [powder 6]", 7.8740, 3.9370, 1.9685, 6)
packer.add_item("250g [powder 7]", 7.8740, 3.9370, 1.9685, 7)
packer.add_item("250g [powder 8]", 7.8740, 3.9370, 1.9685, 8)
packer.add_item("250g [powder 9]", 7.8740, 3.9370, 1.9685, 9)
return packer
def make_doc():
doc = ezdxf.new()
doc.layers.add("FRAME", color=colors.YELLOW)
doc.layers.add("ITEMS")
doc.layers.add("TEXT")
return doc
def main(filename):
bins: List[bp.Bin] = []
for box in ALL_BINS:
packer = build_packer()
packer.add_bin(*box)
packer.pack(bp.PickStrategy.BIGGER_FIRST)
bins.extend(packer.bins)
doc = make_doc()
bp.export_dxf(doc.modelspace(), bins, offset=(0, 20, 0))
doc.saveas(filename)
if __name__ == "__main__":
main("py3dbp_example.dxf")
.. image:: gfx/binpacking-example.png
.. seealso::
- `example1`_ script
- `example2`_ script
Packer Classes
--------------
.. autoclass:: AbstractPacker
.. attribute:: bins
List of containers to fill.
.. attribute:: items
List of items to pack into the :attr:`bins`.
.. autoproperty:: is_packed
.. autoproperty:: unfitted_items
.. automethod:: __str__
.. automethod:: append_bin
.. automethod:: append_item
.. automethod:: get_fill_ratio
.. automethod:: get_capacity
.. automethod:: get_total_weight
.. automethod:: get_total_volume
.. automethod:: pack
Packer
~~~~~~
.. autoclass:: Packer
.. automethod:: add_bin
.. automethod:: add_item
FlatPacker
~~~~~~~~~~
.. autoclass:: FlatPacker
.. automethod:: add_bin
.. automethod:: add_item
Bin Classes
-----------
.. autoclass:: Bin
.. attribute:: name
Name of then container as string.
.. attribute:: width
.. attribute:: height
.. attribute:: depth
.. attribute:: max_weight
.. autoproperty:: is_empty
.. automethod:: __str__
.. automethod:: copy
.. automethod:: reset
.. automethod:: put_item
.. automethod:: get_capacity
.. automethod:: get_total_weight
.. automethod:: get_total_volume
.. automethod:: get_fill_ratio
Box Class
~~~~~~~~~
.. autoclass:: Box
Envelope Class
~~~~~~~~~~~~~~
.. autoclass:: Envelope
Item Class
~~~~~~~~~~
.. autoclass:: Item
.. attribute:: payload
Arbitrary Python object.
.. attribute:: width
.. attribute:: height
.. attribute:: depth
.. attribute:: weight
.. autoproperty:: bbox
.. autoproperty:: rotation_type
.. autoproperty:: position
.. automethod:: copy
.. automethod:: __str__
.. automethod:: get_volume
.. automethod:: get_dimension
.. automethod:: get_transformation
FlatItem Class
~~~~~~~~~~~~~~
.. autoclass:: FlatItem
Functions
---------
.. autofunction:: shuffle_pack
Enums
-----
RotationType
~~~~~~~~~~~~
.. autoclass:: RotationType
.. attribute:: WHD
.. attribute:: HWD
.. attribute:: HDW
.. attribute:: DHW
.. attribute:: DWH
.. attribute:: WDH
PickStrategy
~~~~~~~~~~~~
.. autoclass:: PickStrategy
.. attribute:: BIGGER_FIRST
.. attribute:: SMALLER_FIRST
.. attribute:: SHUFFLE
Credits
-------
- `py3dbp`_ package by Enzo Ruiz Pelaez
- `bp3d`_ by `gedex` - github repository on which `py3dbp`_ is based, written in Go
- Optimizing three-dimensional bin packing through simulation (`PDF`_)
.. _py3dbp: https://github.com/enzoruiz/3dbinpacking
.. _bp3d: https://github.com/gedex/bp3d
.. _PyPI: https://pypi.org/project/py3dbp/
.. _Wikipedia: https://en.wikipedia.org/wiki/Bin_packing_problem
.. _example1: https://github.com/mozman/ezdxf/blob/master/examples/addons/binpacking.py
.. _example2: https://github.com/mozman/ezdxf/blob/master/examples/addons/binpacking2.py
.. _PDF: https://github.com/enzoruiz/3dbinpacking/blob/master/erick_dube_507-034.pdf
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