Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

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MRx
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by MRx »

Another one -- it's also documented inside the project.

from that point it can't be broken down further anymore (this is the smallest example):
intersectingHole4.FCStd
(60.16 KiB) Downloaded 28 times
IoY1jk.png
IoY1jk.png (71.67 KiB) Viewed 1828 times
3GYSyQ.png
3GYSyQ.png (67.09 KiB) Viewed 1828 times
user1234
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by user1234 »

It have something to do with the geometric kernel and the floating values and operations and their tolerances while operating boolean operations, due consecutive floating fault, since all boolean operations works numerical, not 100% in base algebra

This is also that direct modeling programs suffers and can destroy the model, which happens to yours. This is also when a Sketch of a model is not good constrained. The Sketch is solved, but somewhere in the last digit the issue happens. And then while refining the model gets invalid and often anywhere, but not where the issue is, like yours. This is also the reason, why all objects in boolean operations should overlap. And this is the reason, why some firms the operations like this is not allowed.
chrisb
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by chrisb »

drmacro wrote: Tue Nov 23, 2021 6:33 pm As you can see the geom check returns no problem.
Just to make sure: is BOPCheck enabled?
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chrisb
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by chrisb »

MRx wrote: Tue Nov 23, 2021 6:50 pm Another one
I can confirm the result of the geometry check. For me it is another hint to use refine only if really needed; and definitely not as default.
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MRx
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by MRx »

yes bob check is enabled.

In my case refining is absolutely necessary.
It's clear how to avoid it keep the history and don't refine. Just practically it doesn't work due to excessive file size and slowing down the loading time.

From what I read from other posts people always write about tolerances, but how to fix that?
Is it worth to continue discussing it in the FreeCAD forum or should it be passed on to Opencascade?
chrisb
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by chrisb »

MRx wrote: Wed Nov 24, 2021 12:46 am yes bob check is enabled.
I had pinged drmacro on this.
Is it worth to continue discussing it in the FreeCAD forum or should it be passed on to Opencascade?
Most of these are OCC issues.
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TheMarkster
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by TheMarkster »

Add a very tiny (0.05 mm) chamfer to the problematic edge. This will often resolve this error.
MRx
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by MRx »

Thank you, that workaround seems to do it!
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adrianinsaval
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by adrianinsaval »

MRx wrote: Wed Nov 24, 2021 12:46 am yes bob check is enabled.
BOP check often gives false positives according to OCC people themselves, don't mind them if the model still works for further operations.
see: https://forum.freecadweb.org/viewtopic. ... ve#p210302
drmacro
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Re: Intersecting Holes (BOPAlgo_InvalidCurveOnSurface)

Post by drmacro »

adrianinsaval wrote: Wed Nov 24, 2021 1:26 pm
MRx wrote: Wed Nov 24, 2021 12:46 am yes bob check is enabled.
BOP check often gives false positives according to OCC people themselves, don't mind them if the model still works for further operations.
see: https://forum.freecadweb.org/viewtopic. ... ve#p210302
How many further operations? One, two, ten? ;)
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