Roof Arch_remove displaced result

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brjhaverkamp
Posts: 112
Joined: Thu Sep 24, 2015 3:14 pm

Roof Arch_remove displaced result

Postby brjhaverkamp » Fri Mar 08, 2019 4:32 pm

Hi all,

Here is my next puzzle with my attic project, and possibly an other bug.
I was cleaning up my model, based on the things I learned about the Arch workbench.
So last evening I tried to replace the boolean subtract of the holes for the dormers in my roof with a Arch-Remove.
However, the result is a off by a distance of about 80 cm. This could be the placement offset that I gave the roof wrt the floorplan it is based upon.

Or am I overlooking something? All suggestions are welcome.

I have added the example file and a screenshot of my puzzle below
Screenshot (26).png
Screenshot (26).png (355.45 KiB) Viewed 389 times
Kind regards,

Bert
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Roof subtraction.FCStd
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regis
Posts: 655
Joined: Sun Jul 12, 2015 8:17 am
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Re: Roof Arch_remove displaced result

Postby regis » Fri Mar 08, 2019 4:56 pm

hard to guesstimate what's wrong with your stuffs at this point, honestly I can't tell what's wrong with your model after looking at it. My best suggestion is just delete the Roof holes and create a new one.
Roy_043
Posts: 504
Joined: Thu Dec 27, 2018 12:28 pm

Re: Roof Arch_remove displaced result

Postby Roy_043 » Sat Mar 09, 2019 1:54 pm

Fixing this is relatively easy: instead of changing the placement of the 'Roof', change the placement of the underlying sketch. The same approach that was used for 'Roof holes'.
I am inclined to call what you are seeing a bug. You could argue that the Z of the 'Roof' logically has an impact on nested objects. But you would then expect the solid of the 'Roof holes' to be in a higher position.
brjhaverkamp
Posts: 112
Joined: Thu Sep 24, 2015 3:14 pm

Re: Roof Arch_remove displaced result

Postby brjhaverkamp » Thu Mar 14, 2019 10:40 am

Thanks for checking and confirming Roy,

I suspect the z-offset of roof is the cause for this mismatch of the holes. If you think about it: the holes are at exactly the place they would have been if the roof didn't have that z-offset. giving the hole structure the same offset is indeed a valid workaround to get the holes in the intended place.

But I solved it locally now by moving to a boolean subtract because arch_remove became too problematic for now:

The reason is that even though there There is even a second "bug" with the arch_remove method: I use the resulting roof-with-holes to rcut the edges of the walls underneath the roof. But that Arch_remove does not take the holes in the roof into account. So it even cuts the walls where the dormers are placed. Apparently nesting Arch_removes is not working very well.

I posed the question on the goal of Arch_remove in general in the other thread. When that one settles into a conclusion I plan to create a bugreport for both of these issues.

Bert
paullee
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Joined: Wed May 04, 2016 3:58 pm

Re: Roof Arch_remove displaced result

Postby paullee » Thu Mar 14, 2019 5:29 pm

brjhaverkamp
Posts: 112
Joined: Thu Sep 24, 2015 3:14 pm

Re: Roof Arch_remove displaced result

Postby brjhaverkamp » Sun Mar 17, 2019 8:55 am

I created a bug for this on Mantis to keep track.

https://www.freecadweb.org/tracker/view.php?id=3909

Regards,

Bert