Crash happened because we were addressing `.id()` of already deleted `cost_item`.
Surprisingly for me on windows addressing `cost_item` was causing crash too but `cost_item.id()` worked fine.
Now we do not rely on small offset to keep using inner curves to create linings, if some part of the lining is not present (which happens on mullions and transoms) we'll create U or L shape extrusion instead of rectangle with inner curve.
Long story short - this should keep ifc for windows valid.
From this - https://i.imgur.com/hQuCcR3.png
To this - https://i.imgur.com/qZ2Lyfo.png
It's a bit hacky since we still use really small offsets to keep "The outer curve shall enclose all inner curves." rule for IfcArbitraryProfileDefWithVoids valid.
To test, go into add-on preferences and enable "Should Stream". Then load an IFC-SPF in advanced mode, and disable "Load Geometry" before loading (the geometry iterator doesn't work with streaming).
f attributes holding entity lists are expanded in SQL, this means that you end up with significantly more rows. Also, you cannot have the ifc_id marked as a UNIQUE field / benefit from unique primary key index. So leaving the fields as JSON is actually significantly more efficient (almost 10X faster to load a model into BBIM).
Added new panel. in shader graph N-panel that allows you to create fully GLTF and IFC compatible shader graphs by just tweaking parameters from the panel. Note that it's still saved to IFC only when you hit "Save Current Style", before that it's still just stored in blender.
https://imgur.com/a/vmkoLPH
The premise is that if you want to have non-external style you'd be able to create it entirely from this panel - so there will no need to guess or to remember which parameters from the graph are supported by IFC and which are not.
It's still work in progress, still need to polish it, add support for more reflectance methods and add suport for textures (need to be able to import/export it with .ifc and set them from this panel).
Thomas Krijnen
