Problem Exporting object created with boolean

[brjhaverkamp]

Hello all,

It is great to see freecad made another great step. I have version 0.20 installed now and it looks beautiful!
Thanks to everyone involved creating this.

I stumbled on something strange (and I don't think this is specific for v0.20, but I didn't take the trouble testing it with 0.19)
I have created a large object with partdesign and used the boolean there to cut some specific smaller sections to print: topsection, midsection and endsection.

However exporting those sections to stl files posed quite a challenge. I think I figured it out, but is very unintuitive, and possibly even a bug.
Please let me explain, and let me know if my observation is correct or not. Maybe the explanation is a bit lengthy, but I wanted to be complete and detailed enough. The freecad file is also attached.

1) When I export the object with only the boolean visible, but the subelements not toggled visible AND the boolean selected in the treeview, like in the figure below -> the resulting stl file is empty, or more exactly just 84 bytes of header. Prusasliser throws an error when trying to load it

Screenshot from 2022-06-18 17-33-40.png (53.83 KiB) Viewed 797 times

2) When I export the object with the boolean visible, and one of the subelements toggled visible AND the boolean selected in the treeview like in the figure below, -> the whole subelement is placed in the stl file.

Screenshot from 2022-06-18 17-36-43.png (54.04 KiB) Viewed 797 times

3)When I export the object with the boolean visible, and both the subelements toggled visible AND the boolean selected in the treeview like in the figure below, -> the union of the subelements is placed in the stl file.

Screenshot from 2022-06-18 17-37-15.png (53.9 KiB) Viewed 797 times

In all three cases, the view in the main window shows the correctly cut part, so I assumed that what I see is exported.

4) Only if I don't select the boolean in the treeview, but the full Body, is the part correctly exported. It doesn't matter in that case what I have visible in the treeview.

Screenshot from 2022-06-18 17-52-29.png (53.44 KiB) Viewed 797 times

For completeness, I imported all resulting parts in prusaslicer to show what I mean.

Screenshot from 2022-06-18 17-49-04.png (79.25 KiB) Viewed 797 times

My mistake (with hindsight) was that I clicked on the part in the main view to select it. That selects the boolean in the treeview. And depending on what subbody is visible, the result is different. I only discovered by accident that selecting the full body gives the right export.

Let me know if this is a usability bug, or part of the learning curve

Kind regards,

Bert

Code: Select all

OS: Ubuntu 22.04 LTS (ubuntu:GNOME/ubuntu)
Word size of FreeCAD: 64-bit
Version: 0.20.29177 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 0.20)
Hash: 68e337670e227889217652ddac593c93b5e8dc94
Python 3.9.13, Qt 5.12.9, Coin 4.0.0, Vtk 9.1.0, OCC 7.5.3
Locale: English/United States (en_US)

[chrisb]

I don't think it's a bug. You have to select the right object in the tree for export. Selecting in 3D view can do unwanted things, perhaps even more so with the PartDesign booleans, which are rarely used.

[brjhaverkamp]

Hi Chris,

I know now how to deal with it. So for me it is not a problem. But I would argue that _at least_ it is a usability interface bug. I have always selected the part that I want to export in the 3D view. It lights up green and then you can export. So this behavior is quite confusing, esp to newer users.

And arguably it also blocks wider adoption of the boolean function in PartDesign. In the past I have been hit by this issue/bug/feature before. In the end I then reverted back to the boolean in the Parts workbench. It was only because of the new 0.20 version that I tried a bit longer to figure out what was happening.

Bert

[chrisb]

But I would argue that _at least_ it is a usability interface bug.

I am very reluctant with the notion of a bug. Being incenvenient or even very inconvenient or cumbersome doesn't make it necessarily a bug.