Module Contents

ifcopenshell.api.material.add_constituent.add_constituent(file, constituent_set=None, material=None) None

Adds a new constituent to a constituent set

A constituent describes how a portion of an object is made out of a material whereas other portions of the object is made out of other materials. For example, a window might be made out of an aluminium frame and a glass panel. The aluminium used for the frame is one constituent of the material, and glass would be another constituent. Another example might be concrete, where one constituent might be cement, and another constituent might be binder. In the case of the window, the constituent is represented explicitly by the geometry of the window frame and the geometry of the window panel. In the case of a concrete slab, the constituents might be represented in terms of percentages.

Constituents are not available in IFC2X3.

  • constituent_set (ifcopenshell.entity_instance) – The IfcMaterialConstituentSet that the constituent is part of. The constituent set represents a group of constituents. See ifcopenshell.api.material.add_material_set for information on how to add a constituent set.

  • material (ifcopenshell.entity_instance) – The IfcMaterial that the constituent is made out of.


The newly created IfcMaterialConstituent

Return type:



# Let's imagine we have a window type that has an aluminium frame
# and a glass glazing panel. Notice we are assigning to the type
# only, as all occurrences of that type will automatically inherit
# the material.
window_type = ifcopenshell.api.run("root.create_entity", model, ifc_class="IfcWindowType")

# First, let's create a constituent set. This will later be assigned
# to our window element.
material_set = ifcopenshell.api.run("material.add_material_set", model,
    name="Window", set_type="IfcMaterialConstituentSet")

# Let's create a few materials, it's important to also give them
# categories. This makes it easy for model recipients to do things
# like "show me everything made out of aluminium / concrete / steel
# / glass / etc". The IFC specification states a list of categories
# you can use.
aluminium = ifcopenshell.api.run("material.add_material", model, name="AL01", category="aluminium")
glass = ifcopenshell.api.run("material.add_material", model, name="GLZ01", category="glass")

# Now let's use those materials as two constituents in our set.
ifcopenshell.api.run("material.add_constituent", model,
    constituent_set=material_set, material=aluminium)
ifcopenshell.api.run("material.add_constituent", model,
    constituent_set=material_set, material=glass)

# Great! Let's assign our material set to our window type.
# We're technically not done here, we might want to add geometry to
# our window too, but to keep this example simple, geometry is
# optional and it is enough to say that this window is made out of
# aluminium and glass.
ifcopenshell.api.run("material.assign_material", model, products=[window_type], material=material_set)