modeling-app/docs/kcl-std/functions/std-solid-union.md

title, subtitle, excerpt, layout

title	subtitle	excerpt	layout
union	Function in std::solid	Union two or more solids into a single solid.	manual

Union two or more solids into a single solid.

union(
  @solids: [Solid; 2+],
  tolerance?: number(Length),
): [Solid; 1+]

Arguments

Name	Type	Description	Required
solids	[Solid; 2+]	The solids to union.	Yes
tolerance	number(Length)	Defines the smallest distance below which two entities are considered coincident, intersecting, coplanar, or similar. For most use cases, it should not be changed from its default value of 10^-7 millimeters.	No

Returns

[Solid; 1+]

Examples

// Union two cubes using the stdlib functions.


fn cube(center, size) {
  return startSketchOn(XY)
    |> startProfile(at = [center[0] - size, center[1] - size])
    |> line(endAbsolute = [center[0] + size, center[1] - size])
    |> line(endAbsolute = [center[0] + size, center[1] + size])
    |> line(endAbsolute = [center[0] - size, center[1] + size])
    |> close()
    |> extrude(length = 10)
}

part001 = cube(center = [0, 0], size = 10)
part002 = cube(center = [7, 3], size = 5)
  |> translate(z = 1)

unionedPart = union([part001, part002])

// Union two cubes using operators.
// NOTE: This will not work when using codemods through the UI.
// Codemods will generate the stdlib function call instead.


fn cube(center, size) {
  return startSketchOn(XY)
    |> startProfile(at = [center[0] - size, center[1] - size])
    |> line(endAbsolute = [center[0] + size, center[1] - size])
    |> line(endAbsolute = [center[0] + size, center[1] + size])
    |> line(endAbsolute = [center[0] - size, center[1] + size])
    |> close()
    |> extrude(length = 10)
}

part001 = cube(center = [0, 0], size = 10)
part002 = cube(center = [7, 3], size = 5)
  |> translate(z = 1)

// This is the equivalent of: union([part001, part002])
unionedPart = part001 + part002

// Union two cubes using the more programmer-friendly operator.
// NOTE: This will not work when using codemods through the UI.
// Codemods will generate the stdlib function call instead.


fn cube(center, size) {
  return startSketchOn(XY)
    |> startProfile(at = [center[0] - size, center[1] - size])
    |> line(endAbsolute = [center[0] + size, center[1] - size])
    |> line(endAbsolute = [center[0] + size, center[1] + size])
    |> line(endAbsolute = [center[0] - size, center[1] + size])
    |> close()
    |> extrude(length = 10)
}

part001 = cube(center = [0, 0], size = 10)
part002 = cube(center = [7, 3], size = 5)
  |> translate(z = 1)

  // This is the equivalent of: union([part001, part002])
  // Programmers will understand `|` as a union operation, but mechanical engineers
// will understand `+`, we made both work.
unionedPart = part001 | part002