CrossSection
manifold-3d / manifold-encapsulated-types / CrossSection
Class: CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:102
二维横截面，保证从构建之初起就不存在自相交以及多边形之间的重叠现象。该类借助 Clipper2 库实现多边形裁剪（布尔运算）和偏移操作。
See
Constructors
decompose()
decompose():
CrossSection[]
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:370
This operation returns a vector of CrossSections that are topologically disconnected, each containing one outline contour with zero or more holes.
Returns
CrossSection[]
circle()
staticcircle(radius,circularSegments?):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:138
Constructs a circle of a given radius.
Parameters
radius
number
Radius of the circle. Must be positive.
circularSegments?
number
Number of segments along its diameter. Default is calculated by the static Quality defaults according to the radius.
Returns
CrossSection
square()
staticsquare(size?,center?):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:128
Constructs a square with the given XY dimensions. By default it is positioned in the first quadrant, touching the origin. If any dimensions in size are negative, or if all are zero, an empty Manifold will be returned.
Parameters
size?
number | readonly [number, number]
The X, and Y dimensions of the square.
center?
boolean
Set to true to shift the center to the origin.
Returns
CrossSection
Basics
Constructor
new CrossSection(
contours,fillRule?):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:115
Create a 2d cross-section from a set of contours (complex polygons). A boolean union operation (with Positive filling rule by default) is performed to combine overlapping polygons and ensure the resulting CrossSection is free of intersections.
Parameters
contours
A set of closed paths describing zero or more complex polygons.
fillRule?
The filling rule used to interpret polygon sub-regions in contours.
Returns
CrossSection
delete()
delete():
void
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:435
Frees the WASM memory of this CrossSection, since these cannot be garbage-collected automatically.
Returns
void
Boolean
add()
add(
other):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:288
Boolean union
Parameters
other
Polygons | CrossSection
Returns
CrossSection
intersect()
intersect(
other):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:300
Boolean intersection
Parameters
other
Polygons | CrossSection
Returns
CrossSection
subtract()
subtract(
other):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:294
Boolean difference
Parameters
other
Polygons | CrossSection
Returns
CrossSection
compose()
staticcompose(polygons):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:362
Construct a CrossSection from a vector of other Polygons (batch boolean union).
Parameters
polygons
readonly (Polygons | CrossSection)[]
Returns
CrossSection
difference()
Call Signature
staticdifference(a,b):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:313
Boolean difference of the cross-section b from the cross-section a
Parameters
a
Polygons | CrossSection
b
Polygons | CrossSection
Returns
CrossSection
Call Signature
staticdifference(polygons):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:333
Boolean difference of the tail of a list of cross-sections from its head
Parameters
polygons
readonly (Polygons | CrossSection)[]
Returns
CrossSection
intersection()
Call Signature
staticintersection(a,b):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:320
Boolean intersection of the cross-sections a and b
Parameters
a
Polygons | CrossSection
b
Polygons | CrossSection
Returns
CrossSection
Call Signature
staticintersection(polygons):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:338
Boolean intersection of a list of cross-sections
Parameters
polygons
readonly (Polygons | CrossSection)[]
Returns
CrossSection
union()
Call Signature
staticunion(a,b):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:306
Boolean union of the cross-sections a and b
Parameters
a
Polygons | CrossSection
b
Polygons | CrossSection
Returns
CrossSection
Call Signature
staticunion(polygons):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:327
Boolean union of a list of cross-sections
Parameters
polygons
readonly (Polygons | CrossSection)[]
Returns
CrossSection
Convex Hull
hull()
hull():
CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:347
Compute the convex hull of the contours in this CrossSection.
Returns
CrossSection
hull()
statichull(polygons):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:353
Compute the convex hull of all points in a list of polygons/cross-sections.
Parameters
polygons
readonly (Polygons | CrossSection)[]
Returns
CrossSection
Information
area()
area():
number
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:401
Return the total area covered by complex polygons making up the CrossSection.
Returns
number
bounds()
bounds():
Rect
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:426
Returns the axis-aligned bounding rectangle of all the CrossSection's vertices.
Returns
isEmpty()
isEmpty():
boolean
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:407
Does the CrossSection (not) have any contours?
Returns
boolean
numContour()
numContour():
number
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:419
The number of contours in the CrossSection.
Returns
number
numVert()
numVert():
number
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:413
The number of vertices in the CrossSection.
Returns
number
Input & Output
toPolygons()
toPolygons():
SimplePolygon[]
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:392
Return the contours of this CrossSection as a list of simple polygons.
Returns
ofPolygons()
staticofPolygons(contours,fillRule?):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:386
Create a 2d cross-section from a set of contours (complex polygons). A boolean union operation (with Positive filling rule by default) is performed to combine overlapping polygons and ensure the resulting CrossSection is free of intersections.
Parameters
contours
A set of closed paths describing zero or more complex polygons.
fillRule?
The filling rule used to interpret polygon sub-regions in contours.
Returns
CrossSection
Transformations
extrude()
extrude(
height,nDivisions?,twistDegrees?,scaleTop?,center?):Manifold
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:159
Constructs a manifold by extruding the cross-section along Z-axis.
Parameters
height
number
Z-extent of extrusion.
nDivisions?
number
Number of extra copies of the crossSection to insert into the shape vertically; especially useful in combination with twistDegrees to avoid interpolation artifacts. Default is none.
twistDegrees?
number
Amount to twist the top crossSection relative to the bottom, interpolated linearly for the divisions in between.
scaleTop?
number | readonly [number, number]
Amount to scale the top (independently in X and Y). If the scale is 0, a pure cone is formed with only a single vertex at the top. Default 1.
center?
boolean
If true, the extrusion is centered on the z-axis through the origin as opposed to resting on the XY plane as is default.
Returns
mirror()
mirror(
ax):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:225
Mirror this CrossSection over the arbitrary axis described by the unit form of the given vector. If the length of the vector is zero, an empty CrossSection is returned. This operation can be chained. Transforms are combined and applied lazily.
Parameters
ax
readonly [number, number]
the axis to be mirrored over
Returns
CrossSection
offset()
offset(
delta,joinType?,miterLimit?,circularSegments?):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:259
Inflate the contours in CrossSection by the specified delta, handling corners according to the given JoinType.
Parameters
delta
number
Positive deltas will cause the expansion of outlining contours to expand, and retraction of inner (hole) contours. Negative deltas will have the opposite effect.
joinType?
The join type specifying the treatment of contour joins (corners). Defaults to Round
miterLimit?
number
The maximum distance in multiples of delta that vertices can be offset from their original positions with before squaring is applied, when the join type is Miter (default is 2, which is the minimum allowed). See the Clipper2 MiterLimit page for a visual example.
circularSegments?
number
Number of segments per 360 degrees of JoinType::Round corners (roughly, the number of vertices that will be added to each contour). Default is calculated by the static Quality defaults according to the radius.
Returns
CrossSection
revolve()
revolve(
circularSegments?,revolveDegrees?):Manifold
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:173
Constructs a manifold by revolving this cross-section around its Y-axis and then setting this as the Z-axis of the resulting manifold. If the contours cross the Y-axis, only the part on the positive X side is used. Geometrically valid input will result in geometrically valid output.
Parameters
circularSegments?
number
Number of segments along its diameter. Default is calculated by the static Defaults.
revolveDegrees?
number
Returns
rotate()
rotate(
degrees):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:204
Applies a (Z-axis) rotation to the CrossSection, in degrees. This operation can be chained. Transforms are combined and applied lazily.
Parameters
degrees
number
degrees about the Z-axis to rotate.
Returns
CrossSection
scale()
scale(
v):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:213
Scale this CrossSection in space. This operation can be chained. Transforms are combined and applied lazily.
Parameters
v
number | readonly [number, number]
The vector to multiply every vertex by per component.
Returns
CrossSection
simplify()
simplify(
epsilon?):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:280
Remove vertices from the contours in this CrossSection that are less than the specified distance epsilon from an imaginary line that passes through its two adjacent vertices. Near duplicate vertices and collinear points will be removed at lower epsilons, with elimination of line segments becoming increasingly aggressive with larger epsilons.
It is recommended to apply this function following Offset, in order to clean up any spurious tiny line segments introduced that do not improve quality in any meaningful way. This is particularly important if further offseting operations are to be performed, which would compound the issue.
Parameters
epsilon?
number
minimum distance vertices must diverge from the hypothetical outline without them in order to be included in the output (default 1e-6)
Returns
CrossSection
transform()
transform(
m):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:185
Transform this CrossSection in space. Stored in column-major order. This operation can be chained. Transforms are combined and applied lazily.
Parameters
m
The affine transformation matrix to apply to all the vertices. The last row is ignored.
Returns
CrossSection
translate()
Call Signature
translate(
v):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:194
Move this CrossSection in space. This operation can be chained. Transforms are combined and applied lazily.
Parameters
v
readonly [number, number]
The vector to add to every vertex.
Returns
CrossSection
Call Signature
translate(
x,y?):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:195
Move this CrossSection in space. This operation can be chained. Transforms are combined and applied lazily.
Parameters
x
number
y?
number
Returns
CrossSection
warp()
warp(
warpFunc):CrossSection
Defined in: manifold-3d/manifold-encapsulated-types.d.ts:236
Move the vertices of this CrossSection (creating a new one) according to any arbitrary input function, followed by a union operation (with a Positive fill rule) that ensures any introduced intersections are not included in the result.
Parameters
warpFunc
(vert) => void
A function that modifies a given vertex position.
Returns
CrossSection