PrusaSlicer-NonPlainar/src/libnest2d

Introduction

Libnest2D is a library and framework for the 2D bin packaging problem. Inspired from the SVGNest Javascript library the project is
built from scratch in C++11. The library is written with a policy that it should be usable out of the box with a very simple interface but has to be customizable to the very core as well. The algorithms are defined in a header only fashion with templated geometry types. These geometries can have custom or already existing implementation to avoid copying or having unnecessary dependencies.

A default backend is provided if the user of the library just wants to use it out of the box without additional integration. This backend is reasonably fast and robust, being built on top of boost geometry and the polyclipping library. Usage of this default backend implies the dependency on these packages but its header only as well.

This software is currently under construction and lacks a throughout documentation and some essential algorithms as well. At this stage it works well for rectangles and convex closed polygons without considering holes and concavities.

Holes and non-convex polygons will be usable in the near future as well. The no fit polygon based placer module combined with the first fit selection strategy is now used in the Slic3r application's arrangement feature. It uses local optimization techniques to find the best placement of each new item based on some features of the arrangement.

In the near future I would like to use machine learning to evaluate the placements and (or) the order if items in which they are placed and see what results can be obtained. This is a different approach than that of SVGnest which uses genetic algorithms to find better and better selection orders. Maybe the two approaches can be combined as well.

References

• SVGNest
• An effective heuristic for the two-dimensional irregular bin packing problem
• Complete and robust no-fit polygon generation for the irregular stock cutting problem
• Applying Meta-Heuristic Algorithms to the Nesting Problem Utilising the No Fit Polygon
• A comprehensive and robust procedure for obtaining the nofit polygon using Minkowski sums