ianmackenzie / elm-geometry-prerelease / Polyline3d

A Polyline3d represents a sequence of vertices in 3D connected by line segments. This module contains a variety of polyline-related functionality, such as


type alias Polyline3d =
Geometry.Types.Polyline3d

Constructors

fromVertices : List Point3d -> Polyline3d

Construct a polyline from its vertices:

examplePolyline =
    Polyline3d.fromVertices
        [ Point2d.fromCoordinates ( 0, 0, 0 )
        , Point2d.fromCoordinates ( 1, 0, 0 )
        , Point2d.fromCoordinates ( 1, 2, 0 )
        , Point2d.fromCoordinates ( 1, 2, 3 )
        ]

on : SketchPlane3d -> Polyline2d -> Polyline3d

Construct a 3D polyline lying on a sketch plane by providing a 2D polyline specified in XY coordinates within the sketch plane.

Polyline3d.on SketchPlane3d.yz <|
    Polyline2d.fromVertices
        [ Point2d.fromCoordinates ( 0, 0 )
        , Point2d.fromCoordinates ( 1, 0 )
        , Point2d.fromCoordinates ( 1, 1 )
        , Point2d.fromCoordinates ( 2, 1 )
        ]
--> Polyline3d.fromVertices
-->     [ Point3d.fromCoordinates ( 0, 0, 0 )
-->     , Point3d.fromCoordinates ( 0, 1, 0 )
-->     , Point3d.fromCoordinates ( 0, 1, 1 )
-->     , Point3d.fromCoordinates ( 0, 2, 1 )
-->     ]

Properties

vertices : Polyline3d -> List Point3d

Get the vertices of a polyline.

Polyline3d.vertices examplePolyline
--> [ Point3d.fromCoordinates ( 0, 0, 0 )
--> , Point3d.fromCoordinates ( 1, 0, 0 )
--> , Point3d.fromCoordinates ( 1, 2, 0 )
--> , Point3d.fromCoordinates ( 1, 2, 3 )
--> ]

segments : Polyline3d -> List LineSegment3d

Get the individual segments of a polyline.

Polyline3d.segments examplePolyline
--> [ LineSegment3d.fromEndpoints
-->     ( Point3d.fromCoordinates ( 0, 0, 0 )
-->     , Point3d.fromCoordinates ( 1, 0, 0 )
-->     )
--> , LineSegment3d.fromEndpoints
-->     ( Point3d.fromCoordinates ( 1, 0, 0 )
-->     , Point3d.fromCoordinates ( 1, 2, 0 )
-->     )
--> , LineSegment3d.fromEndpoints
-->     ( Point3d.fromCoordinates ( 1, 2, 0 )
-->     , Point3d.fromCoordinates ( 1, 2, 3 )
-->     )
--> ]

length : Polyline3d -> Basics.Float

Get the overall length of a polyline (the sum of the lengths of its segments).

Polyline3d.length examplePolyline
--> 6

boundingBox : Polyline3d -> Maybe BoundingBox3d

Get the minimal bounding box containing a given polyline. Returns Nothing if the polyline has no vertices.

Polyline3d.boundingBox examplePolyline
--> Just
-->     (BoundingBox3d.fromExtrema
-->         { minX = 0
-->         , maxX = 1
-->         , minY = 0
-->         , maxY = 2
-->         , minZ = 0
-->         , maxZ = 3
-->         }
-->     )

Transformations

Transforming a polyline is equivalent to transforming each of its vertices.

scaleAbout : Point3d -> Basics.Float -> Polyline3d -> Polyline3d

Scale a polyline about the given center point by the given scale.

point =
    Point3d.fromCoordinates ( 1, 0, 0 )

Polyline3d.scaleAbout point 2 examplePolyline
--> Polyline3d.fromVertices
-->     [ Point3d.fromCoordinates ( -1, 0, 0 )
-->     , Point3d.fromCoordinates ( 1, 0, 0 )
-->     , Point3d.fromCoordinates ( 1, 4, 0 )
-->     , Point3d.fromCoordinates ( 1, 4, 6 )
-->     ]

rotateAround : Axis3d -> Basics.Float -> Polyline3d -> Polyline3d

Rotate a polyline around the given axis by the given angle (in radians).

examplePolyline
    |> Polyline3d.rotateAround Axis3d.z (degrees 90)
--> Polyline3d.fromVertices
-->     [ Point3d.fromCoordinates ( 0, 0, 0 )
-->     , Point3d.fromCoordinates ( 0, 1, 0 )
-->     , Point3d.fromCoordinates ( -2, 1, 0 )
-->     , Point3d.fromCoordinates ( -2, 1, 3 )
-->     ]

translateBy : Vector3d -> Polyline3d -> Polyline3d

Translate a polyline by the given displacement.

displacement =
    Vector3d.fromComponents ( 1, 2, 3 )

Polyline3d.translateBy displacement examplePolyline
--> Polyline3d.fromVertices
-->     [ Point3d.fromCoordinates ( 1, 2, 3 )
-->     , Point3d.fromCoordinates ( 2, 2, 3 )
-->     , Point3d.fromCoordinates ( 2, 4, 3 )
-->     , Point3d.fromCoordinates ( 2, 4, 6 )
-->     ]

translateIn : Direction3d -> Basics.Float -> Polyline3d -> Polyline3d

Translate a polyline in a given direction by a given distance;

Polyline3d.translateIn direction distance

is equivalent to

Polyline3d.translateBy
    (Vector3d.withLength distance direction)

mirrorAcross : Plane3d -> Polyline3d -> Polyline3d

Mirror a polyline across the given plane.

Polyline3d.mirrorAcross Plane3d.xz examplePolyline
--> Polyline3d.fromVertices
-->     [ Point3d.fromCoordinates ( 0, 0, 0 )
-->     , Point3d.fromCoordinates ( 1, 0, 0 )
-->     , Point3d.fromCoordinates ( 1, -2, 0 )
-->     , Point3d.fromCoordinates ( 1, -2, 3 )
-->     ]

projectOnto : Plane3d -> Polyline3d -> Polyline3d

Find the orthographic projection of a polyline onto a plane. This will flatten the polyline.

Polyline3d.projectOnto Plane3d.xz examplePolyline
--> Polyline3d.fromVertices
-->     [ Point3d.fromCoordinates ( 0, 0, 0 )
-->     , Point3d.fromCoordinates ( 1, 0, 0 )
-->     , Point3d.fromCoordinates ( 1, 0, 0 )
-->     , Point3d.fromCoordinates ( 1, 0, 3 )
-->     ]

mapVertices : (Point3d -> Point3d) -> Polyline3d -> Polyline3d

Transform each vertex of a polyline by the given function. All other transformations can be defined in terms of mapVertices; for example,

Polyline3d.mirrorAcross plane

is equivalent to

Polyline3d.mapVertices (Point3d.mirrorAcross plane)

Coordinate conversions

relativeTo : Frame3d -> Polyline3d -> Polyline3d

Take a polyline defined in global coordinates, and return it expressed in local coordinates relative to a given reference frame.

localFrame =
    Frame3d.atPoint
        (Point3d.fromCoordinates ( 1, 2, 3 ))

Polyline3d.relativeTo localFrame examplePolyline
--> Polyline3d.fromVertices
-->     [ Point3d.fromCoordinates ( -1, -2, -3 )
-->     , Point3d.fromCoordinates ( 0, -2, -3 )
-->     , Point3d.fromCoordinates ( 0, 0, -3 )
-->     , Point3d.fromCoordinates ( 0, 0, 0 )
-->     ]

placeIn : Frame3d -> Polyline3d -> Polyline3d

Take a polyline considered to be defined in local coordinates relative to a given reference frame, and return that polyline expressed in global coordinates.

localFrame =
    Frame3d.atPoint
        (Point3d.fromCoordinates ( 1, 2, 3 ))

Polyline3d.placeIn localFrame examplePolyline
--> Polyline3d.fromVertices
-->     [ Point3d.fromCoordinates ( 1, 2, 3 )
-->     , Point3d.fromCoordinates ( 2, 2, 3 )
-->     , Point3d.fromCoordinates ( 2, 4, 3 )
-->     , Point3d.fromCoordinates ( 2, 4, 6 )
-->     ]

projectInto : SketchPlane3d -> Polyline3d -> Polyline2d

Project a polyline into a given sketch plane. Conceptually, this finds the orthographic projection of the polyline onto the plane and then expresses the projected polyline in 2D sketch coordinates.

Polyline3d.projectInto Plane3d.xy examplePolyline
--> Polyline2d.fromVertices
-->     [ Point2d.fromCoordinates ( 0, 0 )
-->     , Point2d.fromCoordinates ( 1, 0 )
-->     , Point2d.fromCoordinates ( 1, 2 )
-->     , Point2d.fromCoordinates ( 1, 2 )
-->     ]