Subtract an object from an Arch component without modifying the object

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hko
Posts: 96
Joined: Thu Apr 23, 2020 10:44 pm

Subtract an object from an Arch component without modifying the object

Post by hko »

I noticed something about arch component subtractions:

There are three ways to add subtractions: 1) use Arch Remove, 2) via task panel and 3) editing Subtractions property in the property editor.

Unexpectedly (not mentioned in the documentation), Arch Remove produces a different result than the other two:
  • If I "Arch Remove" beam B from a partially intersecting beam A, the beam B is hidden and its object style properties are modified so that transparency is 80 and colours are changed, which can be seen if it is made visible again. In addition to A's geometry modification, that is.
  • If I add B to A's subtractions via task panel or the property editor, B is hidden but its object style properties are not modified. If I make it visible again, it looks like a normal beam.
  • I could swear that I saw a difference between 2) and 3) as well (B wasn't hidden when using the property editor) but I can't reproduce that anymore.
Anyway, it seems useful to me to subtract something but leave it visible in its normal form (no style property modifications). In my actual beam case I have beams A and B. The beam A has a mortise for the beam B. B also intersects two walls and needs to be subtracted from those as well. I'd like to see the mortise and the wall subtractions if I temporarily hide B, but otherwise B should be visible.

I wonder if this could be a clickable option when using Arch Remove?

Code: Select all

OS: Ubuntu 20.04.4 LTS (KDE/plasma)
Word size of FreeCAD: 64-bit
Version: 0.20.24436 (Git)
Build type: Debug
Branch: master
Hash: bf527ba5ed9cbde0813e702c2f3793fb55f5be7c
Python 3.8.10, Qt 5.12.8, Coin 4.0.0, Vtk 7.1.1, OCC 7.3.0
Locale: English/United States (en_US)
Installed mods: 
  * 3DfindIT 1.2.0
  * Render 2022.1.0
  * BIM 2021.12.0
  * Manipulator 1.4.5
  * parts_library
  * dodo
paullee
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Re: Subtract an object from an Arch component without modifying the object

Post by paullee »

Maybe you can share your file to illustrate the behaviour? :)
hko
Posts: 96
Joined: Thu Apr 23, 2020 10:44 pm

Re: Subtract an object from an Arch component without modifying the object

Post by hko »

paullee wrote: Tue Jul 19, 2022 2:19 pm Maybe you can share your file to illustrate the behaviour? :)
Sure, please see the attached screenshot and the FreeCAD file.

Beam (the upper one in the screenshot) was "subtracted" from Column using Arch Remove. After that I made the Beam visible again.

Beam001 was added to Column001's subtractions by editing Column001's Subtractions property. Then it was made visible again. I get the same result if I edit subtractions via the task panel.

To reiterate: object style property changes made by Arch Remove are not documented. Also, I wish one could avoid them and leave the subtracted object visible, perhaps with corresponding clickable options.

subtractions.png
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paullee
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Re: Subtract an object from an Arch component without modifying the object

Post by paullee »

OK, understand the behaviour. It seems there would have no problem with most case though your case is indeed very valid :)

Maybe an option to be added ? An dialog comes up for the first time to set the default action ?

Any developer would like to comment and implement ? :D
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Roy_043
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Re: Subtract an object from an Arch component without modifying the object

Post by Roy_043 »

The new color is based on the Draft construction mode color (Draft_ToggleConstructionMode). It should be possible to only apply the view (and visibility?) changes if Draft construction mode is active.
hko
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Joined: Thu Apr 23, 2020 10:44 pm

Re: Subtract an object from an Arch component without modifying the object

Post by hko »

Roy_043 wrote: Sat Jul 23, 2022 9:20 am The new color is based on the Draft construction mode color (Draft_ToggleConstructionMode). It should be possible to only apply the view (and visibility?) changes if Draft construction mode is active.
The wiki page says "If construction mode is on new Draft objects, except Draft Points, are placed in a dedicated group and given a predefined color."

In my example the beam is not created when Arch Remove is used so I don't see why construction mode should affect it even if it was active.
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Roy_043
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Re: Subtract an object from an Arch component without modifying the object

Post by Roy_043 »

Yes, but we can change the construction mode behavior to accommodate your wishes, and keep the users who prefer the old Arch_Remove behavior happy as well.
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