[Closed] Issue #5854 - Solver failing on certain sketch (was: Solver issue)

[chrisb]

The attached file shows unwanted behaviour.
The sketch has one DOF and can be turned around the origin. Thus it should be possible to fully constrain it with a vertical constraint (consuming one DOF) - on the selcted line:

Bildschirmfoto 2018-12-22 um 20.15.10.png (28.4 KiB) Viewed 1522 times

.
However, if I apply such a constraint the Sketch claims to be overconstrained.

ping

OS: macOS High Sierra (10.13)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15310 (Git)
Build type: Release
Branch: (HEAD detached at c88a64e8e)
Hash: c88a64e8e7a3bb66a23b965b655b5a5040dfa4d2
Python version: 2.7.15
Qt version: 5.11.2
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: German/Germany (de_DE)

[abdullah]

The attached file shows unwanted behaviour.
The sketch has one DOF and can be turned around the origin. Thus it should be possible to fully constrain it with a vertical constraint (consuming one DOF) - on the selcted line:Bildschirmfoto 2018-12-22 um 20.15.10.png.
However, if I apply such a constraint the Sketch claims to be overconstrained.

ping

OS: macOS High Sierra (10.13)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15310 (Git)
Build type: Release
Branch: (HEAD detached at c88a64e8e)
Hash: c88a64e8e7a3bb66a23b965b655b5a5040dfa4d2
Python version: 2.7.15
Qt version: 5.11.2
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: German/Germany (de_DE)

If I select that line and set a vertical constraint I get a green fully constrained sketch in:

OS: Ubuntu 18.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15470 (Git)
Build type: Release
Branch: master
Hash: ab916fefe74d289ff4439924a83508cad54a8c09
Python version: 2.7.15rc1
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.3.0

OS: Ubuntu 18.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15481 (Git)
Build type: DEBUG
Branch: master
Hash: 763b5c362fe4b98dca858f86f5d1353075224651
Python version: 3.6.7
Qt version: 5.9.5
Coin version: 4.0.0a
OCC version: 7.3.0

I have not worked in the solver for the last half a year, so your version should be ok, but I cannot reproduce it.

[chrisb]

Tried on Ubuntu and still the same result. I even downloaded again from the forum - still the same.

OS: Ubuntu 16.04.5 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15481 (Git)
Build type: Release
Branch: master
Hash: 763b5c362fe4b98dca858f86f5d1353075224651
Python version: 2.7.12
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)

[abdullah]

Sorry!! The autoremove redundant was tricking me (and it is the first time).

It would auto remove constraint 16 and wrongly report it as fully constraint even though if it was not.

It is a good example of where the current sketcher fails. Please add it to a GCS ticket, so that next year I work to improve it.

Thanks for reporting this one.

[chrisb]

Somehow the animated gif is not working. Can anyone see the selection and application of the vertical constraint?

[chrisb]

Created Ticket issue #3745.

[openBrain]

Somehow the animated gif is not working. Can anyone see the selection and application of the vertical constraint?

GIF works for some seconds then the cyclic playing seems to break and picture is frozen.

Created Ticket issue #3745.

Bug not reproducible here. Vertical constraint is perfectly applied on the line and sketch turns all green with fully constrained message.

OS: Ubuntu 18.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15441 (Git)
Build type: Release
Branch: master
Hash: c43adafb127f1238bedcb0d2033be3e9e8f7494e
Python version: 2.7.15rc1
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)

[abdullah]

Bug not reproducible here. Vertical constraint is perfectly applied on the line and sketch turns all green with fully constrained message.

OS: Ubuntu 18.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15441 (Git)
Build type: Release
Branch: master
Hash: c43adafb127f1238bedcb0d2033be3e9e8f7494e
Python version: 2.7.15rc1
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)

Have you unchecked "auto remove redundants"?

With it checked the result is a bad result. The sketch shows green, fully constrained, but the outer dimension is gone and now you can drag and drop the outer edge. That is at least what is happening to me.

[openBrain]

Have you unchecked "auto remove redundants"?

With it checked the result is a bad result. The sketch shows green, fully constrained, but the outer dimension is gone and now you can drag and drop the outer edge. That is at least what is happening to me.

I never use this option (don't like much the "auto things") but as I read your previous post, I paid attention to that. And yes, it is unchecked.
I also verified that no existing constraint gone when I apply the vertical one. And I confirm that vertical constraint is correctly applied as an extra one that allows the sketch to be fully constrained (as one may expect).

[chrisb]

If I switch to DogLeg solver in Advanced solver control the sketch is solved as expected. LevenbergMarquardt shows the behaviour described above.

Concerning the GIF, I had enabled 5 repetitions instead of endless. I will leave it as is, since Abdullah is able to reproduce the error.