[OpenSCAD fast-cfg] MeshTools ConvexHullDecorator.py ValueError: operands could not be broadcast together

[dizcza]

I'm generating an STL file out of the OpenSCAD file Helmholtz.scad (-D partnum=9) with and without fast-cfg AND fast-csg-trust-corefinement flags enabled.

I've uploaded the two versions of the same file on Dropbox.

• part9_fast.stl with fast-cfg
• part9_normal.stl without any optimization flags

OpenSCAD 2022.09.05.ai12123 nightly build, Linux.

With the fast-cfg enabled, Mesh -> Split Into Parts command in the MeshTools throws me the following error:

Traceback (most recent call last):
  File "cura/Scene/ConvexHullDecorator.py", line 212, in recomputeConvexHull
    hull_node = ConvexHullNode.ConvexHullNode(self._node, self.getPrintingArea(), self._raft_thickness, self._root)
  File "cura/Scene/ConvexHullDecorator.py", line 187, in getPrintingArea
    printing_area = self.getConvexHull()
  File "cura/Scene/ConvexHullDecorator.py", line 120, in getConvexHull
    return self._compute2DConvexHull()
  File "cura/Scene/ConvexHullDecorator.py", line 276, in _compute2DConvexHull
    return self._offsetHull(self._2d_convex_hull_mesh_result)
  File "cura/Scene/ConvexHullDecorator.py", line 409, in _offsetHull
    result = convex_hull.scale(scale_factor, [center.x, center.z])  # Yes, use Z instead of Y. Mixed conventions there with how the OpenGL coordinates are transmitted.
  File "UM/Math/Polygon.py", line 172, in scale
    point_data = numpy.lib.pad(self._points, ((0, 0), (0, 1)), "constant", constant_values = (1))  # Turn 3D to do an affine transformation.
  File "<__array_function__ internals>", line 5, in pad
  File "numpy/lib/arraypad.py", line 743, in pad
  File "numpy/lib/arraypad.py", line 518, in _as_pairs
  File "<__array_function__ internals>", line 5, in broadcast_to
  File "numpy/lib/stride_tricks.py", line 411, in broadcast_to
  File "numpy/lib/stride_tricks.py", line 348, in _broadcast_to
ValueError: operands could not be broadcast together with remapped shapes [original->remapped]: (2,2)  and requested shape (1,2)

Thread 0x00007f5fba7fc640 (most recent call first):
  File "/tmp/.mount_Ultima1w7bsN/share/cura/plugins/USBPrinting/USBPrinterOutputDeviceManager.py", line 88 in _updateThread
  File "threading.py", line 946 in run
  File "threading.py", line 1009 in _bootstrap_inner
  File "threading.py", line 966 in _bootstrap

Thread 0x00007f5fbb7fe640 (most recent call first):
  File "threading.py", line 324 in wait
  File "zeroconf/__init__.py", line 2534 in wait
  File "zeroconf/__init__.py", line 1715 in run
  File "threading.py", line 1009 in _bootstrap_inner
  File "threading.py", line 966 in _bootstrap

Thread 0x00007f5fbbfff640 (most recent call first):
  File "threading.py", line 324 in wait
  File "threading.py", line 600 in wait
  File "/tmp/.mount_Ultima1w7bsN/share/cura/plugins/UM3NetworkPrinting/src/Network/ZeroConfClient.py", line 81 in _handleOnServiceChangedRequests
  File "threading.py", line 946 in run
  File "threading.py", line 1009 in _bootstrap_inner
  File "threading.py", line 966 in _bootstrap

Thread 0x00007f5fc0efe640 (most recent call first):
  File "zeroconf/__init__.py", line 1369 in run
  File "threading.py", line 1009 in _bootstrap_inner
  File "threading.py", line 966 in _bootstrap

Thread 0x00007f5fc16ff640 (most recent call first):
  File "/tmp/.mount_Ultima1w7bsN/share/cura/plugins/RemovableDriveOutputDevice/RemovableDrivePlugin.py", line 61 in _updateThread
  File "threading.py", line 946 in run
  File "threading.py", line 1009 in _bootstrap_inner
  File "threading.py", line 966 in _bootstrap

Thread 0x00007f5ffa7fc640 (most recent call first):
  File "threading.py", line 320 in wait
  File "threading.py", line 460 in acquire
  File "UM/JobQueue.py", line 98 in _nextJob
  File "UM/JobQueue.py", line 124 in run
  File "threading.py", line 1009 in _bootstrap_inner
  File "threading.py", line 966 in _bootstrap

Thread 0x00007f5ffaffd640 (most recent call first):
  File "threading.py", line 320 in wait
  File "threading.py", line 460 in acquire
  File "UM/JobQueue.py", line 98 in _nextJob
  File "UM/JobQueue.py", line 124 in run
  File "threading.py", line 1009 in _bootstrap_inner
  File "threading.py", line 966 in _bootstrap

Thread 0x00007f5ffb7fe640 (most recent call first):
  File "threading.py", line 320 in wait
  File "threading.py", line 460 in acquire
  File "UM/JobQueue.py", line 98 in _nextJob
  File "UM/JobQueue.py", line 124 in run
  File "threading.py", line 1009 in _bootstrap_inner
  File "threading.py", line 966 in _bootstrap

Thread 0x00007f5ffbfff640 (most recent call first):
  File "threading.py", line 320 in wait
  File "threading.py", line 460 in acquire
  File "UM/JobQueue.py", line 98 in _nextJob
  File "UM/JobQueue.py", line 124 in run
  File "threading.py", line 1009 in _bootstrap_inner
  File "threading.py", line 966 in _bootstrap

Current thread 0x00007f6029dfa000 (most recent call first):
  File "cura/CrashHandler.py", line 397 in _logInfoWidget
  File "cura/CrashHandler.py", line 182 in _createDialog
  File "cura/CrashHandler.py", line 86 in __init__
  File "cura_app.py", line 165 in exceptHook
  File "UM/Qt/QtApplication.py", line 414 in exec
  File "cura/CuraApplication.py", line 888 in run
  File "cura_app.py", line 239 in <module>

Without the fast-cfg flag in OpenSCAD, the rendered STL file is parsed OK in the MeshTools and is split successfully.

The reason to post the issue:

• in MeshTools: the resulting stl file looks OK and perhaps can be printed. So MeshTools should handle such cases.
• in OpenSCAD: fast-cfg is an experimental feature

[dizcza]

Let me know if I should transfer the issue to OpenSCAD github page.