Advanced python IFC + computational geometry 

Guest lecturer • Thomas Krijnen • past: Post-doctoral researcher @ TU Delft, NL • past: PhD @ TU Eindhoven, NL • Founder AECgeeks • Maintainer IfcOpenShell.org • ✉ [email protected] • 🐤 @aothms 

Why python - Batteries included: - web: flask, django, e.g view.ifcopenshell.org - machine learning: pytorch, tensorflow, keras, scikit, … - geometry: pythonOCC, shapely, … - graphs: networkx, rdflib, … - Readable syntax, reasonable semantics wrt typing, expressive types (e.g sets, containment operators, …) - Interpreted (no lengthy compilation times) and high performance possible (e.g numpy, numba, pypy, …) 

Work (1) - geometric analysis for code compliance checking https://github.com/opensourceBIM/voxelization_toolkit 

Work (2) - model validation https://github.com/buildingSMART/validate 

Setup https://docs.conda.io/en/latest/miniconda.html conda create -n course2022 conda activate course2022 conda install -c conda-forge pythonocc-core ifcopenshell jupyter 

Anatomy of a simple Python script 

Data extraction using IfcOpenShell Python 

Entities and attributes 

Inverse attributes 

Comparison with a SPARQL query basic graph pattern aggregate function / makes this a property path, a sequence of two predicates in this used because in IfcOWL the specific type of the property nominal is emitted. IfcAreaMeasure in this case. 

Example with geometry 

The complexity of IFC 

Continue on http://web.archive.org/web/20200711032105/http://www. pythonocc.org/quick-examples/machine-learning-and- building-models/ https://academy.ifcopenshell.org/posts/using-ifcopenshell- and-pythonocc-to-construct-new-geometry/ https://github.com/AECgeeks/tue-python-workshop-2022