Boolean operations and transformations

Operations on lists of parts and the transformations. The operators +, - and * and the methods of the objects are listed with their classes. See Boolean operations for the guide.

Unify(parts: list[Face | Shape | Wire | Compound], /, multithreaded: bool = True, *, id: str | None = None) → Shape

The union of all faces and shapes, or of all wires (their connected chains), as a balanced tree of pairwise unions.

A region has the properties of the faces it holds, merged in list order; compounds give their parts.

Parameters:

parts – faces, shapes, wires and compounds.
multithreaded – True runs the pairwise unions in parallel.
id – the id of what it returns (of a list’s items id.1, id.2, …, of a dict’s id.key); default the kind that made it and a number, given when first asked for.

Raises:

TypeError – an item is not a Face, Shape, Wire or Compound.

Examples

px.Unify([a, b, c])
px.Unify(parts, multithreaded=False)

Subtract(parts: list[Face | Shape | Wire], /, multithreaded: bool = True, *, id: str | None = None) → Shape

The first part minus the union of all others; every region keeps the properties of the first one’s face.

Parameters:

parts – faces, shapes and wires, the first the one subtracted from.
multithreaded – True runs the pairwise operations in parallel.
id – the id of what it returns (of a list’s items id.1, id.2, …, of a dict’s id.key); default the kind that made it and a number, given when first asked for.

Raises:

TypeError – an item is not a Face, Shape or Wire (a Compound: px.Unify merges it first).

Examples

px.Subtract([plate, hole])
px.Subtract([plate, *holes], multithreaded=False)

Intersect(parts: list[Face | Shape | Wire], /, multithreaded: bool = True, *, id: str | None = None) → Shape

The intersection of all faces and shapes, as a balanced tree of pairwise intersections.

Every region keeps the first one’s properties, maxh and minh the smallest of the faces it lies in.

Parameters:

parts – faces, shapes and wires.
multithreaded – True runs the pairwise intersections in parallel.
id – the id of what it returns (of a list’s items id.1, id.2, …, of a dict’s id.key); default the kind that made it and a number, given when first asked for.

Raises:

TypeError – an item is not a Face, Shape or Wire (a Compound: px.Unify merges it first).

Examples

px.Intersect([a, b])
px.Intersect(parts, multithreaded=False)

Glue(parts: list[Face | Shape | Wire | Compound], /, *, id: str | None = None) → Shape

The parts as one shape, as netgen’s occ.Glue: everything cut against everything, every area covered by a different set of faces a face of its own (A - B, A * B, B - A).

The faces’ properties merge in list order, the first winning an overlap; a part lying entirely inside another keeps its own region and properties; touching faces share their edge; a wire through a face splits it into two faces with its properties, a wire piece inside a face that separates nothing stays an internal edge of it (the mesh follows it). Where parts share an edge their edge properties merge the same way.

Parameters:

parts – faces, shapes, wires and compounds (their contents).
id – the id of what it returns (of a list’s items id.1, id.2, …, of a dict’s id.key); default the kind that made it and a number, given when first asked for.

Raises:

TypeError – an item is not a Face, Shape, Wire or Compound.

Examples

px.Glue([air, iron])
px.Glue([plate, px.Line((1, -1), (1, 3))])

Translation(dh: float, dv: float) → Transformation

Translation(d: tuple[float, float]) → Transformation

The move by (dh, dv) in the plane.

Parameters:

dh – the move along h.
dv – the move along v.
d – the move (dh, dv).

Examples

px.Translation(10, 0)
px.Translation((10, 0))

Rotation(angle: float, center: Point = (0, 0)) → Transformation

The turn by angle counterclockwise about center in the plane.

Parameters:

angle – the angle in degrees.
center – the centre (h, v).

Examples

px.Rotation(90)
px.Rotation(45, center=(5, 0))

The map of the plane taking the chain of lines and arcs a onto b, vertex onto vertex.

A straight chain, a single arc or a circle maps by a similarity (turn, uniform scale, move), other chains by the affine map of the vertices; every vertex and edge midpoint must land. Of the possible pairings it takes the one closest to a translation (orientation kept, the smallest turn).

Parameters:

a – the edges mapped: a wire, face, shape, edge view, edges view, selection, LineEdge, ArcEdge, or a list of them.
b – the edges a lands on, in the same forms.
reverse – True takes the best pairing running the other way.

Raises:

ValueError – a or b has no edges, has a spline, branches or is not one connected chain; they have different numbers of vertices; no map takes a onto b.
TypeError – a or b has no edges to take.

Examples

px.GetTransformation(face.edges[0], face.edges[2])
px.GetTransformation(left, right, reverse=True)