IFCのデータの紐づけ構造を理解したい

slab = model.by_type("IfcSlab")[0]
psets = ifcopenshell.util.element.get_psets(slab)
# {'Pset_SlabCommon': {'ThermalTransmittance': 0.4, 'id': 34536},
#  'AC_Pset_Name': {'Name': 'Bodenplatte', 'id': 34544},
#  'ArchiCADProperties': {'Komplette Element-ID': 'Bodenplatte',
#   'Kompakte Element-ID': 'Bodenplatte',
#   'Name des Sachmerkmal-Objekts': '',
#   'Ursprungsgeschoss': 'Erdgeschoss',
#   'Ebene': 'Decken',
#   'Typ': 'Decke',
#   'Geschützt': False,
#   'Baustoff / Mehrschichtiger Aufbau / Profil / Schraffur': 'Stahlbeton 65690',
#   'Etikettentext': '',
#   'Eindeutige ID': 'E4D9CD4B-CA43-4735-94BD-1FD4376BD455',
#   'Verknüpfte Änderungen': '',
#   'Tragende Funktion': 'Nicht definiert',
#   'Lage': 'Nicht definiert',
#   'Element-Klassifizierung': 'Decke',
#   'Umbau-Status': 'Bestand',
#   'Anzeigen auf Umbau-Filter': 'Alle relevanten Filter',
#   'Struktur - Typ': 'Einfach',
#   'ARCHICAD IFC ID': '1pPHnf7cXCpPsNEnQf8_6B',
#   'Externe IFC ID': '',
#   'Oberfläche oben': 'Beton',
#   'Oberfläche Kante': 'Beton',
#   'Oberfläche unten': 'Beton',
#   'Baustoff/Mehrschichtiges Bauteil': 'Stahlbeton 65690',
# ...
#   'Brutto-Oberflächenbereich der Deckenkanten mit Löchern': 8.8,
#   'Brutto-Volumen de Decke mit Löchern': 24.0,
#   'Höhenwert Oberkante': 0.0,
#   'Höhenwert Unterkante': -0.2,
#   'id': 34643}}

import ifcopenshell.util.element

for storey in model.by_type("IfcBuildingStorey"):
    elements = ifcopenshell.util.element.get_decomposition(storey)
    print(f"There are {len(elements)} located on storey {storey.Name}, they are:")
    for element in elements:
        print(element.Name)

def get_decomposition(element, is_recursive=True):
    """
    Retrieves all subelements of an element based on the spatial decomposition
    hierarchy. This includes all subspaces and elements contained in subspaces,
    parts of an aggreate, all openings, and all fills of any openings.

    :param element: The IFC element
    :type element: ifcopenshell.entity_instance.entity_instance
    :return: The decomposition of the element
    :rtype: list[ifcopenshell.entity_instance.entity_instance]

    Example:

    .. code:: python

        element = file.by_type("IfcProject")[0]
        decomposition = ifcopenshell.util.element.get_decomposition(element)
    """
    queue = [element]
    results = []
    while queue:
        element = queue.pop()
        for rel in getattr(element, "ContainsElements", []):
            queue.extend(rel.RelatedElements)
            results.extend(rel.RelatedElements)
        for rel in getattr(element, "IsDecomposedBy", []):
            queue.extend(rel.RelatedObjects)
            results.extend(rel.RelatedObjects)
        for rel in getattr(element, "HasOpenings", []):
            queue.append(rel.RelatedOpeningElement)
            results.append(rel.RelatedOpeningElement)
        for rel in getattr(element, "HasFillings", []):
            queue.append(rel.RelatedBuildingElement)
            results.append(rel.RelatedBuildingElement)
        for rel in getattr(element, "IsNestedBy", []):
            queue.extend(rel.RelatedObjects)
            results.extend(rel.RelatedObjects)
        if not is_recursive:
            break
    return results

const fs = require("fs");
const WebIFC = require('web-ifc');

async function OpenIfc(filename) {
  const ifcData = fs.readFileSync(filename);
  await ifcapi.Init();
  return ifcapi.OpenModel(ifcData);
}

async function LoadFile(filename) {
  const modelID = await OpenIfc(filename);
  return modelID;
}

const ifcapi = new WebIFC.IfcAPI();
ifcapi.SetWasmPath("");

LoadFile('AC20-FZK-Haus.ifc').then(function(modelID) {
  // IfcWallStandardCase
  const expressID = 15042
  ifcapi.GetFlatMesh(modelID, expressID)
});

- 元データ
#15016= IFCSHAPEREPRESENTATION(#118,'Body','SweptSolid',(#15006));
#15024= IFCSHAPEREPRESENTATION(#375,'Box','BoundingBox',(#15023));
#15037= IFCPRODUCTDEFINITIONSHAPE($,$,(#15016,#15024,#15033));

- #15037から#15016を削除するとエラーになる（Bodyのデータが参照できなくなるので）
#15016= IFCSHAPEREPRESENTATION(#118,'Body','SweptSolid',(#15006));
#15024= IFCSHAPEREPRESENTATION(#375,'Box','BoundingBox',(#15023));
#15037= IFCPRODUCTDEFINITIONSHAPE($,$,(#15024,#15033));

- そこから #15024の 'Box' → 'Body' に変更すると正常
#15016= IFCSHAPEREPRESENTATION(#118,'Body','SweptSolid',(#15006));
#15024= IFCSHAPEREPRESENTATION(#375,'Body','BoundingBox',(#15023));
#15037= IFCPRODUCTDEFINITIONSHAPE($,$,(#15024,#15033));

- #15016を 'Body' → 'Box' に変更するとエラー（Bodyのデータがなくなるので）
#15016= IFCSHAPEREPRESENTATION(#118,'Box','SweptSolid',(#15006));
#15024= IFCSHAPEREPRESENTATION(#375,'Box','BoundingBox',(#15023));
#15037= IFCPRODUCTDEFINITIONSHAPE($,$,(#15016,#15024,#15033));

import ifcopenshell
import ifcopenshell.geom

model = ifcopenshell.open(path)
element = model.by_type('IfcWall')[0]
settings = ifcopenshell.geom.settings()
shape = ifcopenshell.geom.create_shape(settings, element)

element = model.by_type('IfcAnnotation')[0]
settings = ifcopenshell.geom.settings()
shape = ifcopenshell.geom.create_shape(settings, element)

- 元（取得できない）
#15366= IFCSHAPEREPRESENTATION(#15265,'Annotation','Annotation2D',(#15272,#15286,#15302,#15313,#15328,#15339,#15350,#15361));

- 'Body'にしても取得できない
#15366= IFCSHAPEREPRESENTATION(#15265,'Body','Annotation2D',(#15272,#15286,#15302,#15313,#15328,#15339,#15350,#15361));

- テキストも混ざっているので、それらを削除して一つにしても無理( #15286 は `IfcGeometricCurveSet` )
#15366= IFCSHAPEREPRESENTATION(#15265,'Body','Annotation2D',(#15286));

- 形状を壁のものにすると取得できる
#15366= IFCSHAPEREPRESENTATION(#15265,'Body','Annotation2D',(#15006));