[SOLVED]Section view showing hidden stairs

[robocat]

Hi all,

I'm a new FreeCad user and really enjoying the freedom of the software so far, and want to say thanks to everyone involved!

So far I have been using BIM to create a simple model of an apartment. From this I have created a section view that has been inserted onto a page using techdraw ArchView.

The section is of a (building) containing a (floor) containing (walls, stairs, windows, doors and a floor slab).

I have unfortunately run into a quirk where the staircase that descends from a cutout in the Floor_Slab shows fully despite being partly under the Floor_Slab.

I'm still getting to grips with the software so please let me know if I have done something dumb.

Any ideas towards resolving this quirk are greatly appreciated! (Photos Below)
(Tried to attach the freecad file but says its too large)

thanks.
robocat

ArchView.png

3D_View_with_clipping.png

Top View.png

section_plane.png

OS: Windows 10 Version 2009
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24291 (Git)
Build type: Release
Branch: releases/FreeCAD-0-19
Hash: 7b5e18a0759de778b74d3a5c17eba9cb815035ac
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.0
Locale: English/United Kingdom (en_GB)

[bernd]

It would be good to have the file.

you could make a copy of the file and delete some of the heavy objects not related to your problem. Like windows etc. With this it should be possible to get the file less than 1 MB.

[robocat]

Ah yes good idea!
The freecad file is attached below.

[robocat]

Hi all,
Has anyone been able to reproduce this issue and/or find a workaround?

To add some extra info, the sectioning issue does not seem to arise from a set of stairs under a slab in a simple mockup (see file).
From this it can maybe be determined that it is something to do with the walls in my building or the way the arch pieces have been put together?
Or maybe it's something to do with the doors and windows?

thanks

[robocat]

Wall, door and window seem to work fine in my test mockup... (see attechment)

I guess it must be something about the geometry I have specifically created in my file?

I'm pretty stumped

[paullee]

If a Shape2DView is made, it seem ok - except the stair which is not cut is not shown in this way.

It seem the should be hidden stair is shown overlaid on top. Seems something similar happened in earlier case ? Probably a bug.

See if @yorik has a gap to have a look.

Ping

Screenshot from 2021-09-17 20-35-42.png (205.38 KiB) Viewed 3824 times

[robocat]

It seem the should be hidden stair is shown overlaid on top. Seems something similar happened in earlier case ? Probably a bug.

Yes, I agree. It seems that there is an issue with the layering when the view is created, as it puts the stairs on top of everything else.
It is interesting that the second staircase seems to section with no problems though.

[Roy_043]

The issue is related to the stairs. "Riser Thickness" should not be zero. The same applies to "Thread Thickness". Using zero values leads to an invalid solid.

[paullee]

The issue is related to the stairs. "Riser Thickness" should not be zero. The same applies to "Thread Thickness". Using zero values leads to an invalid solid.

Thanks for the hint, but "Riser Thickness" and "Tread Thickness" can be zero as designed

But it turns out "Structure" - "One Stringer" / "Two Stringer" are broken somehow, no idea when it broke, it should worked previously. When this is set to "Massive", everything becomes normal.

So, both Stairs and ArchSection/TechDraw-ArchView has some bug

Ping

Can you help reporting the bugs in Mantis BugTracker?

Thanks

apartment_lite_ r.FCStd

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Screenshot from 2021-09-18 22-34-05.png (204.61 KiB) Viewed 3587 times

Screenshot from 2021-09-18 22-33-53.png (216.84 KiB) Viewed 3587 times

Screenshot from 2021-09-18 22-41-33.png (244.26 KiB) Viewed 3587 times

[Roy_043]

"Riser Thickness" and "Tread Thickness" can be zero as designed

Maybe this needs to be checked. Changing the "Riser Thickness" from 0 to 1 fixes the OP's problem. And if "Riser Thickness" is zero Part_CheckGeometry does report problems. Your "Massive" solution just fixes the invalid solid issue in another way.