Part.OCCError: Bnd_Box is void

I am using a simple script to convert .step to .gltf

import sys
from cqparts import Part
args = sys.argv[1:]
filename = args[0].split(".")[0]
Part.importer('step')(args[0]).exporter('gltf')(filename + '.gltf')

And I get:

File “/home/home/.local/share/virtualenvs/blueprint-z4-87zsQ/lib/python2.7/site- packages/cadquery/freecad_impl/shapes.py”, line 966, in clean r = self.wrapped.removeSplitter()

It happens just with certain files (but they are not corrupt or anything). Any ideas what can be done to avoid this error? Also, it takes 5+ min befoer I get the error (4mb file).

[jan0991]

@fragmuffin thanks for the help, I really appreciate it!

[fragmuffin]

Hi @jan0991, sorry for the delay, I’ve been busy and got distracted.

I think I see the problem, the step file you’re importing has multiple parts, so it’s not a Part, but an Assembly. When calling Part.importer('step') you get back an object that will create a Part class, and return an instance of that class to import the step file you give it (there’s a few steps there)… but you want in importer to return an Assembly instance instead.

So the solution is as simple as exchanging Part for Assembly:

>>> from cqparts import Assembly
>>> from cqparts.display import display
>>> filename = 'CX - 37 BL.STEP'
>>> obj = Assembly.importer('step')(filename)
>>> isinstance(obj, Assembly)
True

display from a console should open a web-browser to display a gltf export

>>> display(obj)

In addition, because the Assembly has nested components, each one can be displayed individually

>>> display(obj.components['185'])

Sadly this list of components is just a sequential index, each component’s name, hierarchy, and colour is lost during this import. An improvement is on the horizon #72, but it’s probably a distant horizon because its priority is a bit low.

The above code is working on the current master with no changes, so I’ll close this issue with the assumption it’ll work on yours too.

Please let me know how you go, and feel free to re-open if I’m wrong 😉 Thank you for the feedback @jan0991 , it’s always good to see what people are doing with cqparts and cadquery.