[Bug] Part tessellate function returns vastly different results when FreeCAD is in console mode

[30350n]

Is there an existing issue for this?

• I have searched the existing issues

Forums discussion

https://forum.freecadweb.org/viewtopic.php?f=22&t=71391

Version

0.20 (Release)

Full version info

OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.20.29177 (Git)
Build type: Release
Branch: releases/FreeCAD-0-20
Hash: 68e337670e227889217652ddac593c93b5e8dc94
Python 3.8.10, Qt 5.15.2, Coin 4.0.1, Vtk 8.2.0, OCC 7.6.2
Locale: English/Germany (en_DE)
Installed mods: 
  * Assembly4 0.12.3
  * ExtremeProDark 1.0.4
  * fasteners 0.4.2
  * fcgear 1.0.0
  * free2ki
  * kicadStepUpMod 10.14.5
  * sheetmetal 0.2.56
  * slic3r-tools
  * ThreadProfile 1.82.0

Subproject(s) affected?

Part

Issue description

The shape.tessellation(...) function returns vastly different meshes, regarding resolution, depending on whether or not your run with or without the FreeCAD gui.

Running the attached script (tessellation_bug.py) on the attached example object like this:
freecadcmd sphere.FCStd tessellation_bug.py results in a mesh with 13360 vertices, while running it normally like this:
freecad sphere.FCStd tessellation_bug.py only results in a mesh with 2505 vertices.

My first thought was that this would be some kind of unit (metric vs. imperial) problem, but I wasn't able to find a constant to reproduce the "gui" version, from the command line.

From further testing, I figured that this mainly seems to affect circular objects, so my best guess is that it's somehow related to some kind of hidden angular deflection value.

Anything else?

tessellation_bug.zip
(contains an example FCStd file: sphere.FCStd and a python script which tessellates the object and prints the number of vertices: tessellation_bug.py)

Code of Conduct

• I agree to follow this project's Code of Conduct

[luzpaz]

Do you mind posting to the forum as well? Lots more traffic there. Just us triagers here.

[30350n]

Done.