Wrong output is generated for closed bent parts

[ceremcem]

Description

If a bent part is closed on itself, start point of unfolded part is determined erroneously.

Here is a closed bent part:

Here is the erroneous unfold:

Workaround

Breaking the loop with a negligible distance fixes the issue:

Here is the correct unfold:

Attachment

Created with LinkStage3@e9c60d4d: simple.fcstd.remove-me.zip

[easyw]

@ceremcem you should need to state that you are using FreeCAD A3 realthunder branch. This is obviously important in your user case ... Links are not implemented by FC main branch...

[ceremcem]

@easyw I stated under the "Attachment" title with the exact commit hash but I understand that you mean stating under the "Description" title (in a more visible manner).

Since this file doesn't use any LinkStage3 feature (no linked documents, no Assembly Container, nothing), I preferred not to underline the LinkStage3 relation. Do you have a chance to reproduce such a drawing with FC main branch? Is it directly related with LinkStage3?

[easyw]

you didn't test it in FC main branch did you? The file cannot even be open cleanly in FC main branch.

[ceremcem]

you didn't test it in FC main branch did you?

No.

The file cannot even be open cleanly in FC main branch.

That's expected, obviously. However, what I asked is creating the drawing from scratch within FC main branch. It's a fairly easy drawing. Here is the steps:

1. Create a 30 mm wide rectangle with PartDesign WB
2. Pad it 2 mm
3. Add a bend at one side
4. Extend the bend eg. 50 mm.
5. Add a bend
6. Extend the bend 30 mm
7. Add a bend
8. Extend the bend eg. 22mm
9. Add a bend to the other side of the first part (created at step 2)
10. Extend that bend 28mm
11. Now the bent part is closed on itself.
12. Try to unfold this geometry

[easyw]

so please create the example and post it here.

[ceremcem]

@easyw You are so nice, thank you. Above steps can be applied to create the sketch from scratch under 2 minutes. I would appreciate if anyone could help the recreation the geometry before I need to download FC source and compile it from scratch.

[easyw]

@ceremcem you are so nice not taking your time to post a sample to work on. Moreover nobody is asking you to build FC from source. You should be smart enough to know there are plenty of FC appimages to be used. It would take then less than the time you spent in your nice reply to download it and make your sample.

[shaise]

This happens on main as well. it looks like the edge bends becomes fused as a single wall, hence the cut is not detected

test_closed_loop_bends.zip

[ceremcem]

@easyw

You should be smart enough to know there are plenty of FC appimages to be used.

Obviously I'm not :) I wasn't aware that FC main branch has appimages available too. I thought the images are only available for Assembly3. Anyway, thanks for letting me know that as this information saved my day today.

[luzpaz]

FYI @ceremcem the AppImage wiki page is auto-updated via script and has the most current appimage links to it. You can obviously also check https://github.com/FreeCAD/FreeCAD/releases/tag/0.19_pre :wink:

[luzpaz]

bump for status