E.g. you select IfcSlab and change it to IfcRoof - since there is not IfcRoofType in IFC2X3 it would figure the matching product type is IfcBeamType (which is confusing too but that's another subject) and change this slab's type object to IfcBeamType which consequently change IfcSlab to IfcBeam instead of IfcRoof that was selected originally.
Noticed investigating #5918
Since calculate_unit_scale now requires a project.
def calculate_unit_scale(ifc_file: ifcopenshell.file, unit_type: str = "LENGTHUNIT") -> float:
"""Returns a unit scale factor to convert to and from IFC project units and SI units.
Example:
.. code:: python
ifc_project_length * unit_scale = si_meters
si_meters / unit_scale = ifc_project_length
:param ifc_file: The IFC file.
:param unit_type: The type of SI unit, defaults to "LENGTHUNIT"
:returns: The scale factor
"""
> if not (units := ifc_file.by_type("IfcProject")[0].UnitsInContext):
E IndexError: list index out of range
If you move a wall, and that wall has features (e.g. openings), it's
desirable to also move those openings (because they are invisible). This
is a special exception to `should_transform_children` because the
definition of the feature (opening) is inherently tied to the parent
(wall).
What wasn't considered is that this would typically then also move
subchildren of the features (e.g. fills like doors). I'm surprised
nobody caught this earlier.
I did also consider another approach where if you move a wall, it moves
all unfilled openings, and if you move a door which fills a opening, it
moves the opening too. Intuitively it sounds nice, but it doesn't work
because:
- Openings can have multiple fillings. If you move all fillings, they
all fight to move the openings.
- All logic about children goes one way: a placement may have child
placements relative to it. This breaks the convention (if moving a door
instead moves its opening) which can make brains explode.
- It starts to conflate rules about relative / referenced placements
with spatial decomposition. We assume all IFCs are valid and follows the
convention of relative placement but we cannot guarantee this. This also
leads to brain explosion.
E.g. in #5890 pset was shared by 2 elements and they it worked is
1) it appended first element and it's rel to pset
2) it appended second element and skipped updating it's rel as it was appended before. Now it's going to update it to ensure it encludes second element too.
I believe, issue occurred after 8c28f52 when we stopped duplicating inverses and started to reuse them.
Richard Brice