fem.simmesh.SimMesh

fem.simmesh.SimMesh(
    name,
    resolution,
    domain=None,
    bounds=None,
    size=None,
    padding=0.1,
    method=MeshMethod.HEX,
    mesher=TetMesher.TETGEN,
)

A declarable, named meshing intent — the scene program’s mesh object.

Attributes

Name	Type	Description
name	str	Mesh identifier (unique within a scene program; studies refer to it via mesh="<name>").
resolution	Any	Sampling-lattice cells per axis (positive int or triplet). Elements for method="hex"; the DC extraction grid for the tet methods (see the module docstring for the honest mapping).
domain	Any	Optional SDF (or plain callable field) selecting which part of the scene participates: when set, :meth:build meshes this field instead of the scene SDF handed to solve/build.
bounds	Any	Lower corner of the meshing box, or None to derive it from the meshed field automatically (coarse inside-scan + padding).
size	Any	Extent of the meshing box; None exactly when bounds is.
padding	float	Extra margin per side used only by the automatic bounds scan.
method	MeshMethodLike	Meshing method — a :class:~cadjoint.enums.MeshMethod or its plain string spelling: "hex" (voxelize+snap HEX8, the fast default), "tet4" (DC surface -> TetGen TET4), or "tet10" (the TET4 mesh promoted to quadratic tets — the quality path). Normalised to the enum on construction.
mesher	TetMesherLike	Which volume mesher fills a tet4/tet10 mesh — a :class:~cadjoint.enums.TetMesher or its string spelling. "tetgen" (the default) is TetGen on the dual-contour surface, sized by the lattice, and every node follows the design through :func:~cadjoint.fem.motion.recompute_tet_points. "gmsh" is :func:cadjoint.fem.gmsh.sdf_gmsh_tet_mesh — the same surface handed to Gmsh’s HXT as an STL, sized by the part, with second-order midsides on a reparametrised surface and every node tagged with the patches that own it. A Gmsh mesh’s nodes follow the design only through the node_map plugin kind, which is the private tier’s: without it the mesh is frozen geometry and :attr:frozen_geometry says so. Ignored for method="hex".

Methods

Name	Description
build	Extract (or reuse) the volume mesh for the current parameters.
describe	JSON-ready declaration payload: everything the viewer displays.
grid	The sampling grid this mesh uses (resolving automatic bounds).
inspect	JSON-ready inspection summary of the built mesh.
quality	Per-element quality metrics of the built mesh.

build

fem.simmesh.SimMesh.build(sdf=None, *, rebuild=False)

Extract (or reuse) the volume mesh for the current parameters.

The result is cached on the instance and reused while the meshing parameters and the meshed field object stay the same; pass rebuild=True after mutating the field’s parameter values in place to force re-extraction.

Parameters

Name	Type	Description	Default
sdf	Any	Scene SDF object or callable field; ignored when the mesh declares a domain, required otherwise.	None
rebuild	bool	Discard the cached mesh and re-extract.	False

Returns

Name	Type	Description
	HexMesh | TetMesh | CutMesh	The extracted :class:~cadjoint.fem.hexmesh.HexMesh
	HexMesh | TetMesh | CutMesh	(method="hex") or :class:~cadjoint.fem.tetmesh.TetMesh
	HexMesh | TetMesh | CutMesh	(method="tet4"/"tet10"; requires tetgen). Tet
	HexMesh | TetMesh | CutMesh	extraction runs :func:~cadjoint.fem.tetmesh.sdf_to_tet_mesh’s
	HexMesh | TetMesh | CutMesh	refinement ladder, which tries exact sharp-feature DC placement
	HexMesh | TetMesh | CutMesh	and the more robust Tikhonov placement at every rung and
	HexMesh | TetMesh | CutMesh	records what it tried on mesh.refinement; when no rung
	HexMesh | TetMesh | CutMesh	works the TetGen error propagates, naming both ends of the
	HexMesh | TetMesh | CutMesh	ladder. The tet grid must fully contain the zero surface
	HexMesh | TetMesh | CutMesh	(unlike voxelization, DC needs the closed boundary).

describe

fem.simmesh.SimMesh.describe()

JSON-ready declaration payload: everything the viewer displays.

The domain entry records the selected object by its name attribute when it has one (the viewer patches it by name) plus its type; meshes without a domain report None.

grid

fem.simmesh.SimMesh.grid(sdf=None)

The sampling grid this mesh uses (resolving automatic bounds).

For method="hex" the grid cells are the candidate elements; for the tet methods it is the DC extraction lattice.

Parameters

Name	Type	Description	Default
sdf	Any	Scene SDF, needed only when the mesh has no domain and automatic bounds must scan the field.	None

inspect

fem.simmesh.SimMesh.inspect(sdf=None)

JSON-ready inspection summary of the built mesh.

Builds the mesh first if needed (same caching as :meth:build).

Returns

Name	Type	Description
	dict[str, Any]	{"name", "method", "nodes", "elements", "bounds": {"min", | | | dict\[str, Any\] | "max"}, "grid": {"origin", "spacing", "cells"}, "quality": | | | dict\[str, Any\] | {...}} where each quality entry is a {"min", "mean", | | | dict\[str, Any\] | "max"} summary over elements. The shape is
	dict[str, Any]	method-agnostic; only the metric names under "quality"
	dict[str, Any]	differ (:meth:quality), so a stats display can iterate them.

quality

fem.simmesh.SimMesh.quality(sdf=None)

Per-element quality metrics of the built mesh.

Builds the mesh first if needed (same caching as :meth:build).

Returns

Name	Type	Description
	dict[str, np.ndarray]	{"scaled_jacobian": (C,), "aspect_ratio": (C,)} float64
	dict[str, np.ndarray]	arrays for hex meshes (see
	dict[str, np.ndarray]	func:~cadjoint.fem.quality.scaled_jacobians /
	dict[str, np.ndarray]	func:~cadjoint.fem.quality.aspect_ratios);
	dict[str, np.ndarray]	{"radius_ratio": (C,), "aspect_ratio": (C,)} for tet
	dict[str, np.ndarray]	meshes (see :func:~cadjoint.fem.quality.tet_radius_ratios /
	dict[str, np.ndarray]	func:~cadjoint.fem.quality.tet_aspect_ratios; TET10 metrics
	dict[str, np.ndarray]	are those of the straight-sided corner tets).