[Bug tracker #4360] Bug in 0.19? BOPcheck fails on pocket of ShapeString

[TedM]

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.21125 (Git)
Build type: Release
Branch: master
Hash: 40600a55c2fe71ff589be677f6e427ccc937d003
Python version: 3.8.2
Qt version: 5.12.5
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)

I think this is a bug and I don't see it reported in the bug tracker. I'm asking for confirmation or to see if I'm in error.

I'm embossing a ShapeString into a solid using a pocket, not going all the way through.

ss1.jpg (171.17 KiB) Viewed 1749 times

Making the pocket works fine and I see no issues with what I've done.

However, Doing Analyze Geometry for Errors with all BopCheck options enabled produces "Pocket: Result has multiple solids. This is not supported at this time" which isn't true. I'm also noticing several Python syntax warnings, which may or may not be associated,

ss2.jpg (196.93 KiB) Viewed 1749 times

(The previous pocket of a sketch of a circle produces no error.

Again, is this a bug or am I missing something?

Thanks

[TheMarkster]

Confirmed:

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.21125 (Git)
Build type: Release
Branch: master
Hash: 40600a55c2fe71ff589be677f6e427ccc937d003
Python version: 3.8.2
Qt version: 5.12.5
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)


It looks like it fails the self-intersection test. A workaround is to convert the shapestring to a sketch using Draft workbench Draft to Sketch tool, then use the sketch. This is not parametric as changes to the shapestring won't get reflected in the sketch or subsequent pocket operation.

[TedM]

Should I add this to the bug tracker?

[chrisb]

Should I add this to the bug tracker?

No. You didn't use the ShapeString for the pocket, so you should remove it from the body. Then CheckGeometry doesn't show errors. I cannot test the following, because I don't have the font, but you may try to use the ShapeString directly for pocketing.

[TedM]

Should I add this to the bug tracker?

No. You didn't use the ShapeString for the pocket, so you should remove it from the body. Then CheckGeometry doesn't show errors. I cannot test the following, because I don't have the font, but you may try to use the ShapeString directly for pocketing.

I'm sorry, but I'm not understanding this answer. I did use the ShapreString directly for the pocket. By the way, it'd not just this font, My actual application used a different one.

It's true I can work around the problem by converting the ShapreString to a sketch but isn't my approach valid? Shouldn't it pass a geometry check?

[kisolre]

So I tried and 0.18.4 and even 0.17.13541 fails with any pocketed shapestring... This is under Windows. Could somebody try to pass BOP check to any pocketed shapestring? It either gives "BOPAlgo OperationAborted" or crashes FreeCAD.

[openBrain]

I'm sorry, but I'm not understanding this answer. I did use the ShapreString directly for the pocket. By the way, it'd not just this font, My actual application used a different one.

No, you don't use the ShapeString to pocket. In the attached file you use a sketch that has the same shape as the ShapeString and this is a problem.
Either delete the ShapeString, or better delete your last pocket and its sketch, and directly pocket the ShapeString.

It's true I can work around the problem by converting the ShapreString to a sketch but isn't my approach valid? Shouldn't it pass a geometry check?

The approach shown in the attached file isn't valid, or at least suboptimal.

[openBrain]

I made from scratch a minimal ShapeString pocketing in PartDesign and confirm the check unexpectedly terminates with a "BOPAlgo OperationAborted".

[chrisb]

I did use the ShapreString directly for the pocket.

This is how the dependency graph of your model looks like. ShapeString is not used for anything:

[TheMarkster]

I think some of you are mistaking my file for the OP's. He did not use a sketch for the pocket. My example for a workaround was to create the sketch and use it for the pocket.