3D offset generates unexpected geometry

[KlumpRasmus]

Describe the bug
When trying to generate an offset (larger) version of an object the result is unexpected.

To Reproduce
Run the code below

Expected behavior
A larger version of the original object, enlarged by 2mm on all faces.

Code reproducing the issue
from openscad import *

fn = 100
c = cube([15, 30, 10]) + [15, -15, 0]
p = hull(c, cylinder(h=7, d=30))
p2 = offset(p, 2)
output(p2)

Screenshots

Environment and Version info (please complete the following information):

• OS: Ubuntu 24.04.1 LTS
• System: ThinkPad x13
• OpenSCAD Version: own build 2025.01.01

Library & Graphics card information
If applicable, add the content of the Help->Library Info window, or the output of running the openscad --info command.

Additional context
Add any other context about the problem here.

[gsohler]

1st guess is that offset has issues with 2 adjacent faces with very similar but not equal angle.
pythonscad will combine those faces by accident and the lost vertix would be the result of only 2 faces meeting in one point.
will try to addresss this ASAP.
I am very confident that an instant way to fix that is to reduce your fn fir the moment

[KlumpRasmus]

Great, thanks. Let me know if I can test anything out.

[gsohler]

This problem will only solve when i update offset to use rounded edges and rounded corners for positive offset values.
With the current implementation the new corner coordinate is not clearly defined if more than 3 faces meet in one corner.
New concept must have extruded arcs as edges and sphere-arcs as corners.