Note
Go to the end to download the full example code.
Walk and filter a real IFC assembly#
The .cad accessor adds walk, find, and flatten for
hierarchical CAD assemblies. walk yields (path, block) pairs;
find filters by metadata predicates; flatten collapses every
leaf to a single-level MultiBlock with path-named blocks.
This example walks a real BIM model, the buildingSMART “Single-family house” sample (CC-BY 4.0, buildingSMART International), and finds all walls by their IFC type, the canonical first step in any BIM analysis.
import pandas as pd
import pyvista as pv
import pyvista_cad
from pyvista_cad.examples import downloads
Read the real IFC building.
Drop stray geo-reference / survey markers placed far from the house.
drop_spatial_outliers uses a robust MAD test on block position
(markers have no reliable IFC class) and preserves the hierarchy, so
the walk below still shows the real building tree.
Walk the tree. Path, IFC type, and cell count.
rows = []
for path, block in root.cad.walk():
n_cells = (
block.n_cells
if isinstance(block, pv.DataSet)
else sum(b.n_cells for b in block if isinstance(b, pv.DataSet))
)
rows.append(
{
'path': str(path),
'kind': type(block).__name__,
'ifc_type': block.field_data.get('cad.ifc_type', [b''])[0],
'cells': n_cells,
}
)
pd.DataFrame(rows)
Find every wall.
walls = root.cad.find(ifc_type='IfcWall')
pd.DataFrame({'path': [str(p) for p, _ in walls]})
Flatten the tree: every leaf becomes a path-named block.
list(root.cad.flatten().keys())
['environment - site/house - site/Single-family house/00 groundfloor/living room/kitchen', 'environment - site/house - site/Single-family house/00 groundfloor/floor', 'environment - site/house - site/Single-family house/00 groundfloor/house - outer wall - house right front', 'environment - site/house - site/Single-family house/00 groundfloor/house - outer wall - house right back', 'environment - site/house - site/Single-family house/00 groundfloor/house - outer wall - house left', 'environment - site/house - site/Single-family house/00 groundfloor/plumbing wall', 'environment - site/house - site/Single-family house/house - gross volume', 'environment - site/house - site/Single-family house/sand bedding', 'living room', 'entry hall', 'house - roof - slab left', 'house - roof - slab right']
Render the building with each element in its own color.
pl = pv.Plotter()
pl.add_mesh(root, multi_colors=True, show_edges=True, edge_color='black')
pl.show()
Total running time of the script: (0 minutes 0.605 seconds)