elementa.cad — API Reference

ElementaCAD

High-level wrapper around the gmsh OpenCASCADE kernel. Manages geometry creation, boolean operations, meshing, and export.

from elementa.cad import ElementaCAD

cad = ElementaCAD(verbose=False)

Constructor

ElementaCAD(verbose: bool = True)

Initialises gmsh if not already initialised, and adds a new gmsh model.

---

2-D Primitives

add_rectangle

def add_rectangle(
    name: str,
    dx: float,
    dy: float,
    center: Tuple[float, float] = (0, 0),
    tag_boundaries: bool = True,
) -> int

Creates a rectangle centred at center with width dx and height dy.
Returns the gmsh surface tag.
Boundary physical groups: <name>_edge_0 … <name>_edge_3.

add_disk

def add_disk(
    name: str,
    rx: float,
    ry: float = None,
    center: Tuple[float, float] = (0, 0),
    tag_boundary: bool = True,
) -> int

Creates an elliptical disk. If ry is omitted, a circle of radius rx is created.

add_polygon

def add_polygon(
    name: str,
    points: List[Tuple[float, float]],
    tag_boundary: bool = True,
) -> int

Creates a planar polygon from a list of (x, y) vertices.

---

3-D Primitives

add_box

def add_box(
    name: str,
    dx: float, dy: float, dz: float,
    center: Tuple[float, float, float] = (0, 0, 0),
    tag_boundaries: bool = True,
) -> int

add_sphere

def add_sphere(
    name: str,
    r: float,
    center: Tuple[float, float, float] = (0, 0, 0),
    tag_boundary: bool = True,
) -> int

add_cylinder

def add_cylinder(
    name: str,
    r: float,
    h: float,
    base_center: Tuple[float, float, float] = (0, 0, 0),
    axis: Tuple[float, float, float] = (0, 0, 1),
    tag_boundary: bool = True,
) -> int

---

Boolean Operations

All boolean methods return a list of resulting entity tags and create named physical groups for the result domain and its boundaries.

boolean_union

def boolean_union(
    entities: List[Tuple[int, int]],
    dim: int,
    name: str = "union",
) -> List[int]

boolean_difference

def boolean_difference(
    objectA: List[Tuple[int, int]],
    subtracts: List[Tuple[int, int]],
    dim: int,
    name: str = "diff",
) -> List[int]

boolean_intersection

def boolean_intersection(
    objs: List[Tuple[int, int]],
    dim: int,
    name: str = "intersect",
) -> List[int]

---

Meshing & Export

generate_mesh

def generate_mesh(dim: int = 2, mesh_size: float = None) -> None

Runs gmsh mesh generation. Set mesh_size to override the global element size.

export

def export(basename: str = "elementa_cad_output") -> None

Writes a .msh file (gmsh version 2.2 format).

finalize

def finalize() -> None

Finalises and frees gmsh resources.