Sketcher Constraints checkbox -- What does it do?

[garya]

Can someone explain or point me to what the check-box to the left of each constraint in the Sketcher Constraints is for? I can't find it described anywhere.

[Reynard1066]

It turns on and off the visibility and selection of the constraint (in red). Sometimes a sketch can get very busy with constraints and selection of end points etc. can be difficult so you can hide the ones that are getting in the way.

[garya]

Ah, thanks. I thought it might do something like that or deactivate them but apparently it doesn't always work. For example, coincidence constraints aren't visible, and turning one off and on doesn't make it visible. That's unfortunate because it makes it difficult to identify which is which unless one renames them. I also have a case where sometimes only one of a constraint pair is made invisible, along with a different constraint; the internal tracking of which text goes with which constraint appears to be confused.
Anyway, thanks, that's a help.
OS: FreeBSD 11.3-RELEASE-p6
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.0.18.4
Build type: Release
Python version: 3.7.6
Qt version: 5.13.2
Coin version: 3.1.3
OCC version: 7.4.0.beta
Locale: C/Default (C)

[chrisb]

the internal tracking of which text goes with which constraint appears to be confused.

Do you hava an example for this?

[garya]

Do you hava an example for this?

Yes, but it's rather complex. I will try to cut it down to something tolerable.

[garya]

In the attached file:

1. Open the sketch in Sketcher WB
2. Scroll down to constraint labelled "UpperGuideSlopLines"
3. Click on it and notice where the two constraint texts are
4. On the right hand constraint, note the "UprRtSlopInLineWithUprRtGuide" constraint label above it
5. Click the "UpperGuideSlopLines" check box to hide it
Result: The right hand constraint label disappears, but not the left; the additional constraint above it disappears

Bug_Sketch_6.FCStd

(13.31 KiB) Downloaded 20 times

OS: FreeBSD 11.3-RELEASE-p6
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.0.18.4
Build type: Release
Python version: 3.7.6
Qt version: 5.13.2
Coin version: 3.1.3
OCC version: 7.4.0.beta
Locale: C/Default (C)

[vocx]

Ah, thanks. I thought it might do something like that or deactivate them but apparently it doesn't always work...

Please note than in 0.19 there is a new tool to activate and deactivate constraints, Sketcher_ToggleActiveConstraint.

[kisolre]

Constraints are not hidden. They are moved to another virtual space and you can switch between the two spaces so you can have two visual sets of constraints. Sketcher_SwitchVirtualSpace

[garya]

Please note than in 0.19 there is a new tool to activate and deactivate constraints, Sketcher_ToggleActiveConstraint.

I noticed that in the docs, thanks.

Constraints are not hidden. They are moved to another virtual space and you can switch between the two spaces so you can have two visual sets of constraints. Sketcher_SwitchVirtualSpace

Ah, thanks.

[garya]

@chrisb Don't know if this is helpful or not, but I've noticed the mismatch in constraint display seems to happen after I have deleted some pieces of a sketch and added new ones. Unfortunately, I haven't noticed exactly when it happens. But maybe something like deleting one arc, inserting a guide line, and then re-creating the arc. This might cause problems with constraints on straight lines that formerly connected to the ends of the deleted arc, even though those constraints were related to the line ends not connected to the arc.