Module Contents

class ifcopenshell.api.style.assign_representation_styles.Usecase
remove_same_type_styles(style_item, current_style_type: str, remove_item: bool) None
ifcopenshell.api.style.assign_representation_styles.assign_representation_styles(file, shape_representation=None, styles=None, replace_previous_same_type_style=True, should_use_presentation_style_assignment=False) None

Assigns a style directly to an object representation

A style may either be assigned directly to an object’s representation, or to a material which is then associated with the object. If both exist, then the style assigned directly to the object’s representation takes precedence. It is recommended to use materials and assign styles to materials. However, sometimes you may want to assign colours directly to the object representation as an override. This API function provides that capability.

If you want to assign styles to a material instead (recommended), then please see ifcopenshell.api.style.assign_material_style.

  • shape_representation (ifcopenshell.entity_instance) – The IfcShapeRepresentation of the object that you want to assign styles to. This implicitly defines the context at which the styles should be used.

  • styles (list[ifcopenshell.entity_instance]) – A list of presentation styles, typically IfcSurfaceStyle. The number of items in the list should correlate with the number of items in the shape_representation’s Items attribute. If you have more items than styles, the last style is used.

  • replace_previous_same_type_style (bool) – Remove previously assigned styles of the same type as currently assign style`. Defaults to True.

  • should_use_presentation_style_assignment (bool) – This is a technical detail to accomodate a bug in Revit. This should always be left as the default of False, unless you are finding that colours aren’t showing up in Revit. In that case, set it to True, but keep in mind that this is no longer a valid IFC. Blame Autodesk.


List of created IfcStyledItems

Return type:



# A model context is needed to store 3D geometry
model3d = ifcopenshell.api.run("context.add_context", model, context_type="Model")

# Specifically, we want to store body geometry
body = ifcopenshell.api.run("context.add_context", model,
    context_type="Model", context_identifier="Body", target_view="MODEL_VIEW", parent=model3d)

# Let's create a new wall. The wall does not have any geometry yet.
wall = ifcopenshell.api.run("root.create_entity", model, ifc_class="IfcWall")

# Let's use the "3D Body" representation we created earlier to add a
# new wall-like body geometry, 5 meters long, 3 meters high, and
# 200mm thick
representation = ifcopenshell.api.run("geometry.add_wall_representation", model,
    context=body, length=5, height=3, thickness=0.2)

# Assign our new body geometry back to our wall
ifcopenshell.api.run("geometry.assign_representation", model,
    product=wall, representation=representation)

# Place our wall at the origin
ifcopenshell.api.run("geometry.edit_object_placement", model, product=wall)

# Create a new surface style
style = ifcopenshell.api.run("style.add_style", model)

# Create a simple grey shading colour and transparency.
ifcopenshell.api.run("style.add_surface_style", model,
    style=style, ifc_class="IfcSurfaceStyleShading", attributes={
        "SurfaceColour": { "Name": None, "Red": 0.5, "Green": 0.5, "Blue": 0.5 },
        "Transparency": 0., # 0 is opaque, 1 is transparent

# Now specifically our wall only will be coloured grey.
ifcopenshell.api.run("style.assign_representation_styles", model,
    shape_representation=representation, styles=[style])