api: docstring improvements across geometry, sequence, and feature modules (#7842)

* Doc clarification for api.sequence.assign_process
* Doc clarification for api.geometry.edit_object_placement
* Doc clarification for api.feature.remove_feature
* Doc clarification for api.geometry.add_wall_representation clippings normal
* regenerate_wall_representation: document BBIM_Boolean preservation requirement

Generated with the assistance of an AI coding tool.

src/ifcopenshell-python/ifcopenshell/api/feature/remove_feature.py

@@ -22,11 +22,13 @@ import ifcopenshell.util.element
 
 
 def remove_feature(file: ifcopenshell.file, feature: ifcopenshell.entity_instance) -> None:
-    """Remove a feature
+    """Permanently delete a feature element and its void or projection relationship.
 
-    Fillings are retained as orphans. Featured elements remain. Features
-    cannot exist by themselves, so not only is the relationship removed, the
-    feature is also removed.
+    The feature entity (e.g. IfcOpeningElement) is removed from the model
+    along with its IfcRelVoidsElement or IfcRelProjectsElement relationship.
+    The host element (wall, slab, etc.) is unaffected. Any fillings (windows,
+    doors) that occupied the opening become orphaned and must be separately
+    deleted via root.remove_product.
 
     :param feature: The IfcFeatureElement to remove.
 

src/ifcopenshell-python/ifcopenshell/api/geometry/add_wall_representation.py

@@ -47,7 +47,9 @@ def add_wall_representation(
     :param thickness: The thickness of the wall in meters.
     :param x_angle: The slope angle along the wall's X-axis, in radians.
     :param clippings: List of clipping definitions. Clippings can be `Clipping` objects
-        or dictionaries of arguments for `Clipping.parse`.
+        or dictionaries of arguments for `Clipping.parse`. Each clipping has a
+        ``normal`` that points toward the removed material (the discarded side),
+        not toward the kept material; see :func:`clip_solid` for details.
     :param booleans: List of any existing IfcBooleanResults.
     :return: IfcShapeRepresentation.
     """

src/ifcopenshell-python/ifcopenshell/api/geometry/edit_object_placement.py

@@ -52,10 +52,11 @@ def edit_object_placement(
     :param is_si: If True, the matrix is given in SI units. If false, in
         project units.
     :param should_transform_children: A child element is a nested element,
-        opening, filling, etc. If true, child elements will move along with the
-        parent. If false, child elements will stay where they are. Because most
-        placements in IFC are relative, this means that if a child moves, we
-        actually don't change their placement.
+        opening, filling, etc. If True, child elements move along with the
+        parent; pass True when moving an assembly (roof, furniture group, etc.)
+        and you want all children to follow. If False (default), child elements
+        keep their current world positions; their local placements are rewritten
+        to compensate for the parent move.
     :return: The new or updated IfcLocalPlacement entity
     """
     usecase = Usecase()

src/ifcopenshell-python/ifcopenshell/api/geometry/regenerate_wall_representation.py

@@ -69,6 +69,12 @@ def regenerate_wall_representation(
     additional extrusions are generated for each connection that boolean
     difference the base extrusion.
 
+    Clippings applied via :func:`geometry.clip_solid` or
+    :func:`geometry.clip_solid_bounded` are preserved only if the ``element``
+    parameter was passed when creating them, which registers the result in the
+    ``BBIM_Boolean`` property set.  Clippings created without that parameter
+    are silently discarded during regeneration.
+
     This will also update the axis line representation (e.g. trim the axis line
     to any connections).
 

src/ifcopenshell-python/ifcopenshell/api/sequence/assign_process.py

@@ -26,7 +26,7 @@ def assign_process(
     relating_process: ifcopenshell.entity_instance,
     related_object: ifcopenshell.entity_instance,
 ) -> ifcopenshell.entity_instance:
-    """Assigns an object to be related to a process, typically a construction task
+    """Assigns an object as an input, control, or resource of a process
 
     Processes work using the ICOM (Input, Controls, Outputs, Mechanisms)
     paradigm in IFC. This process model is commonly used in modeling
@@ -63,6 +63,17 @@ def assign_process(
 
     For resources, any construction resource may be assigned to a task.
 
+    .. warning::
+
+        This function creates an **Input** relationship
+        (``IfcRelAssignsToProcess``), meaning the product is *consumed* or
+        *operated on* by the task — the typical case is demolition or
+        maintenance.
+
+        If the task *constructs or installs* a product (e.g. erecting a wall
+        or fitting a window), use :func:`assign_product` instead, which
+        creates an **Output** relationship (``IfcRelAssignsToProduct``).
+
     :param relating_process: The IfcProcess (typically IfcTask) that the
         input, control, or resource is related to.
     :param related_object: The IfcProduct (for input), IfcCostItem (for
@@ -77,7 +88,7 @@ def assign_process(
         # need to be part of a work schedule.
         schedule = ifcopenshell.api.sequence.add_work_schedule(model, name="Construction Schedule A")
 
-        # Let's create a construction task. Note that the predefined type is
+        # Let's create a demolition task. Note that the predefined type is
         # important to distinguish types of tasks.
         task = ifcopenshell.api.sequence.add_task(model,
             work_schedule=schedule, name="Demolish existing", identification="A", predefined_type="DEMOLITION")
@@ -85,8 +96,12 @@ def assign_process(
         # Let's say we have a wall somewhere.
         wall = ifcopenshell.api.root.create_entity(model, ifc_class="IfcWall")
 
-        # Let's demolish that wall!
+        # The wall is an INPUT to the demolition task (it will be consumed).
         ifcopenshell.api.sequence.assign_process(model, relating_process=task, related_object=wall)
+
+        # For a construction task that BUILDS a wall, use assign_product instead:
+        # build_task = ifcopenshell.api.sequence.add_task(model, ..., predefined_type="CONSTRUCTION")
+        # ifcopenshell.api.sequence.assign_product(model, relating_product=wall, related_object=build_task)
     """
     if related_object.HasAssignments:
         for assignment in related_object.HasAssignments: