[ Bug in Section view ]: Unexpected/incorrect lines

[Piero69]

i get some unspected and incorrect lines in section view (see attachment)

is it a bug?

Code: Select all

OS: Windows 7 Version 6.1 (Build 7601: SP 1)
Word size of FreeCAD: 64-bit
Version: 0.21.30345 (Git)
Build type: Release
Branch: master
Hash: f42a47aa0fd8c4f34ef63c185d9f29b9b6e84737
Python 3.8.13, Qt 5.15.4, Coin 4.0.0, Vtk 9.1.0, OCC 7.6.3
Locale: Italian/Italy (it_IT)
Installed mods: 
  * A2plus 0.4.54b
  * Assembly3 0.11.3
  * Assembly4 0.11.8
  * Behave-Dark-Colors 0.1.1
  * BOLTSFC
  * CurvedShapes 1.0.4
  * Curves 0.5.8
  * dxf_library
  * DynamicData 2.46.0
  * ExplodedAssembly
  * fasteners
  * FCGear
  * ImportNURBS
  * invgears 0.1.2
  * lattice2
  * nurbs
  * Render 2022.1.0
  * Silk -1230293488.0.0
  * symbols_library

[Shalmeneser]

A recompute hide the small line.
But the big one is staying and it's not right.

There is a try to modify the cut algorithm : https://forum.freecadweb.org/viewtopic.php?f=35&t=71670

[wandererfan]

is it a bug?

I think it is, but it looks like an OCC bug. The cut shape looks right:

506271124_cutshape.png (9.42 KiB) Viewed 449 times

But in drawexe the cut shape has the extra lines:

drawexe_extraLines.png (18.33 KiB) Viewed 449 times

I'll play around with it some more, but it looks like we will have to file an upstream bug report.