pyOCCT

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Expected Behavior

I am unable to set the ShapeFix_Wireframe mode to remove small edges via its attribute ModeDropSmallEdges Relatedly, I am also unable to change any of the modes (i.e. FixSolidMode, FixFreeFaceMode, etc) in ShapeFix_Shape

>>> from OCCT.Exchange.Basic import ExchangeBasic
>>> from OCCT.ShapeFix import ShapeFix_Wireframe
>>> my_part = ExchangeBasic.read_step('path/to/my/step.step')
>>> wireframe_fixer = ShapeFix_Wireframe(my_part)
>>> wireframe_fixer.ModeDropSmallEdges = True
>>> wireframe_fixer.ModeDropSmallEdges()
True

Current Behavior

>>> from OCCT.Exchange.Basic import ExchangeBasic
>>> from OCCT.ShapeFix import ShapeFix_Wireframe
>>> my_part = ExchangeBasic.read_step('path/to/my/step.step')
>>> wireframe_fixer = ShapeFix_Wireframe(my_part)
>>> wireframe_fixer.ModeDropSmallEdges = True
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'OCCT.ShapeFix.ShapeFix_Wireframe' object attribute 'ModeDropSmallEdges' is read-only
>>> wireframe_fixer.ModeDropSmallEdges()
False

Possible Solution

This seems to be because those attributes are passed by reference in the C++ libraries, I'm not strong in pybind-fu so I'm not sure what would have to be changed, but I'm willing to try if you point me in the right direction!

Context

I have been having issues with the capping plane feature and I was pointed to these shape healing tools on the OpenCascade forums They work alright, but it is clear that I have some small disconnected edges that need removed and I'm unable to set the attribute.

Your Environment

• Version used: 7.5.2
• Operating System and version (desktop or mobile): Windows 10, Debian Stretch

I guess you intend to use method MergeSmallEdges, note that it has argument theModeDrop which you can set true as a workaround.

Oh interesting I completely missed that. I was intending to run FixSmallEdges, do you know if running MergeSmallEdges with theModeDrop=True followed by FixSmallEdges with ModeDropSmallEdges set to False is equivalent to just running FixSmallEdges with ModeDropSmallEdges set to False?

Seems that the workaround won't help using method FixSmallEdges. In case you don't need to call it on a compound, you should be fine calling CheckSmallEdges and MergeSmallEdges instead. You can check the implementation of FixSmallEdges here , line 408. Lines 421-462 show an involved specific behavior for compounds with a recursive call which is problematic. However if you use any other topology is should suffice to only reimplement lines 463-466 in Python.