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.
It was leaving an orphaned pset if 'products' was a list of all elements pset is assigned to. Then it would create a new pset for each element leaving original pset orphaned.
In IFC it's possible for a property set to be assigned to multiple elements and which may lead to confusing behaviour when you edit a pset on one element and other element seems to get edited too.
Which makes it worse is that that it is possible that some software is might be doing this unintentionally when exporting IFC (as some sort of optimization as storing 1 is more optimal than n copies of it).
So now there are some tools in Bonsai and in IfcOpenShell to handle the shared psest:
1) Indication that property is shared - https://imgur.com/a/9dd3jST (similar to how Blender indicates ID data-block users). You can click on it to "unshare" the pset - a new copy for the pset will be created and it's going to be linked only to the active object.
2) api pset.unshare_pset method that does the same. And util.element.get_elements_using_pset method that encapsulates schema differences and different approaches for occurrences/types.
3) ifcpatch recipe 'UnsharePsets' that's making all property sets in the IFC file to have just 1 element that's using them. You can limit the affected elements by providing query.
ifcpatch recipe is also available in Bonsai - https://i.imgur.com/aOCx7HI.png
Kind of experimental. The idea is that it will reassign class e.g. from IfcWindow to IfcWindowType (or vice versa) and will keep the IFC representations and property sets.
Example - https://imgur.com/a/X7MHR0s
1) For psets there was an issue - it was instantiating abstract IfcProfileProperties
2) For materials it was only able to instantiate IfcExtendedMaterialProperties though there are other pset types too in ifc2x3.
Richard Brice
