[Bug?] Placement issue when saving STP file imported with Link options

[openBrain]

Hi all,

I found a very weird behavior when I save then reopen a STP file that was imported with "Link" options enabled.
Here are the STEP options I use :

STP_options.png (10.84 KiB) Viewed 276 times

Below is what the part looks like when I import then save it (this is an assembly with nested sub-assemblies):

part_save.png (3.84 KiB) Viewed 276 times

Now how the part looks like after I close the file and reopen it !!! :

part_reopen.png (4.67 KiB) Viewed 276 times

Basically assembly is exploded and sub-assemblies are not more well located.
I'm sorry I can't share file or even better screenshots but this is a professional project and it can't be disclosed.
I ATM open this thread so it is reported and known.
If I get some time, I'll try to build a dummy model that reproduces the issue.

[openBrain]

Hi all,

I finally managed to reproduce the bug with a minimal file I can share here.
Actually the problem isn't really STEP import, but a specific issue when certain types of object are nested (namely compound inside link).

To reproduce :

1. Download & open attached file
2. Select the "Rear" compound and rotate it eg. 90° around Y axis (so both pads are one along each other)
3. Save and close the file
4. Reopen the file => Pads are back to their original placement. It appears that compound Placement isn't saved.

I did a test with compound not nested inside link and there is no problem anymore in that case.

bug_assembly.gif (365.1 KiB) Viewed 157 times

Thanks for confirming.

Ping

@realthunder, may that be specific to Link introduction ?

---
OS: Windows 7 SP 1 (6.1)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.18677 (Git)
Build type: Release
Branch: master
Hash: 3cd487064ee7d2b754f250ca2ce29bb0d2c37374
Python version: 3.6.7
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)

[realthunder]

PR submitted here

[openBrain]

PR submitted here

Could you give a clue about what kind of link is the "Product" (root object) one in the file I posted ? I can't figure out how to manually create it (I used a STEP import as base). Thx.

[easyw-fc]

Could you give a clue about what kind of link is the "Product" (root object) one in the file I posted ? I can't figure out how to manually create it (I used a STEP import as base). Thx.

You can use contextual menu (Right click) on Combo tab.
-

link-group.png (35.94 KiB) Viewed 100 times

[openBrain]

You can use contextual menu (Right click) on Combo tab.

Many thanks.
Not a big issue, but I'd prefer it is called "LinkGroup" rather than "Link" in property editor, so it better reflects what it is.

[realthunder]

PR submitted here

Could you give a clue about what kind of link is the "Product" (root object) one in the file I posted ? I can't figure out how to manually create it (I used a STEP import as base). Thx.

I have changed back to use App::Part as the default STEP import container in some pending PR. And that's why LinkGroup is buried inside some menu action. LinkGroup will continue to work regardless.