Package: ladybug-geometry
ladybug-geometryLadybug geometry is a Python library that houses geometry objects and geometry
computations methods used throughout the Ladybug Tools core libraries.The library is designed to work with a wide range of Python environments and
it returns consistent results between them (cPython 2 and 3, IronPython 2).Installationpip install -U ladybug-geometryAPI DocumentationCurrently Supported Capabilities of this LibraryPerform Vector Math (Dot, Cross, Angle, Normalize)Calculate Bounding Box for any Geometry (Min, Max, Center)Subdivide Lines and ArcsCompute Perimeter and Area of Planar GeometryCheck Concavity and Clockwise Ordering of 2D GeometryTriangulate Planar GeometryCompute Mesh Face Areas, Centroids, and NormalsMove Any GeometryRotate Any Geometry Around an AxisMirror (Reflect) Any Geometry Over a PlaneScale Any Geometry from a Base PointCheck if a 2D Point Inside 2D PolygonComputePole of Inaccessibilityfor any 2D PolygonPerform 2D Polygon Boolean Operations (Union, Intersection, Difference)Intersect Colinear 2D Polygon Segments with one Another (for matching lengths)Join Line Segments into PolylinesCalculate 3D Face Plane and Normal from VerticesCompute 3D Face Intersection with a Ray or LineGenerate a Quad Mesh Grid from a 3D FaceGenerate Sub-faces Based on Ratio with a Face (used for window generation)Generate Contours and Contour Fins from a Face (used to generate louvers, fins and overhangs)Split 3D Coplanar Faces with one Another (for matching areas)Solve Adjacencies by Matching 3D Face GeometriesJoin 3D Faces into 3D PolyfacesCheck if a 3D PolyFace is a Closed SolidEnsure All Faces of a Solid 3D PolyFace Point OutwardsCompute the Volume of a Closed 3D PolyfaceCheck if a Point is Inside a Closed 3D PolyfaceOfficially Unsupported Capabilities for which One Must Rely on CAD InterfacesConversion of Curved 3D Surfaces to Planar 3D FacesFancier Meshing (eg. gridded meshing that completely fills the base surface)Solid Boolean Unions (this should not be needed for anything in Ladybug Tools)AcknowledgementsThis library was built by combining capabilities of several different open-source
(MIT Licensed) projects, establishing a set of standardized geometry objects that
allowed them all to talk to one another, and adding several other capabilities
with new code. We as a community owe a huge amount of thanks to the open source projects
that provided many of the starting capabilities of this package and we are indebted
to the developers who made their work available under an MIT license for the betterment
of geometry computation everywhere. Where possible, you will find detailed lists of
references in the docstrings of this package's source code. A summary of the key
sources that were used to build this library are as follows:euclidearcutandearcut-pythonpolybooljsandpypolyboolpolylabelpySTLA countless number ofStackOverflowexperts who answered various geometry questionsA countless number ofWikipediaauthors who described various geometry algorithmsReasons for this LibraryWe initially debated whether the burden of geometry computation should be placed largely
on the CAD environments in which Ladybug Tools operates or whether it should be included
in a dedicated core Python library like this one.As we developed the core libraries, it became clear that there are large advantages
to having it in the core including:Standardized compatibility of geometry between different CAD plugins (eg. Rhino, Revit), simulation engines (eg. E+, Radiance), and file formats (eg. gbXML, GEM).The ability to perform geometry operations from the core library CLI without the need for CAD software.Improved performance (since a dedicated library could be tailored to the use cases of Ladybug Tools).Reliability and maintain-ability in the face of changes to CAD environments and changing Python conventions.Items 1 and 4 above proved to be particularly important and so the decision was made
that the Ladybug Tools core libraries would have its own geometry library that was
distinct from CAD plugins.Before committing to write our own library, we looked into using or tweaking other
comprehensive open source geometry libraries for the core including:Rhino3dmBlender API (bpy)Boost GeometryTopologicHowever, Rhino3dm lacks basic geometry computation. The Blender library had many capabilities
but it only works in Python3 and this could break certain CAD workflows that rely on
IronPython. Boost Geometry (the geometry library used by the OpenStudio SDK) also had a
lot of functionality but it clearly has C dependencies, making it unusable from IronPython.
Topologic also appeared to have C dependencies, though the most relevant issue was
that its dual license could create challenges for certain use cases of Ladybug Tools.After considering the situation further, we realized that many of the capabilities that
we needed could be achieved by building off the work of various open source MIT-licensed
projects as long as we committed to using planar geometry. Since all of the geometry
ultimately going to the engines (Radiance, E+) is planar, we made the decision that
the core libraries will primarily support planar objects with no NURBS support and
very limited support for Arcs, Circles, Spheres, Cylinders and Cones.Thus this repository was born!Local DevelopmentClone this repo locallygit clone git@github.com:ladybug-tools/ladybug-geometry.git#orgit clone https://github.com/ladybug-tools/ladybug-geometry.gitInstall dependencies:cd ladybug-geometrypip install -r dev-requirements.txtpip install -r requirements.txtRun Tests:python -m pytests tests/Generate Documentation:sphinx-apidoc -f -e -d 4 -o ./docs ./ladybug_geometrysphinx-build -b html ./docs ./docs/_build/docs