Construction line has disappeared (v0.19)

Post here for help on using FreeCAD's graphical user interface (GUI).
Forum rules
and Helpful information
IMPORTANT: Please click here and read this first, before asking for help

Also, be nice to others! Read the FreeCAD code of conduct!
garthn555
Posts: 6
Joined: Mon Nov 30, 2020 7:13 pm

Construction line has disappeared (v0.19)

Post by garthn555 »

Sketch in Body is fully constrained but the construction line I used to offset the inner oblong shape is not showing. I need to increase the length of it, but cannot even see it in the constraint list.

I understand that the Sketcher should show construction geometry automatically, although I've tried various options to get it to display with no success

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22960 (Git)
Build type: Release
Branch: master
Hash: c5a4b01d2e4218bcc0eb6650337650a6c65ef0e4
Python version: 3.8.6
Qt version: 5.12.5
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
Attachments
JokoTestPart.FCStd
(333 KiB) Downloaded 26 times
Last edited by garthn555 on Mon Nov 30, 2020 9:12 pm, edited 1 time in total.
User avatar
Kunda1
Veteran
Posts: 13434
Joined: Thu Jan 05, 2017 9:03 pm

Re: Construction line has disappeared (v0.19)

Post by Kunda1 »

Welcome to the forum. Please post your full About info to the OP.
Alone you go faster. Together we go farther
Please mark thread [Solved]
Want to contribute back to FC? Checkout:
'good first issues' | Open TODOs and FIXMEs | How to Help FreeCAD | How to report Bugs
Bance
Veteran
Posts: 4186
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Construction line has disappeared (v0.19)

Post by Bance »

There is no construction line in sketch.
garthn555
Posts: 6
Joined: Mon Nov 30, 2020 7:13 pm

Re: Construction line has disappeared (v0.19)

Post by garthn555 »

Bance wrote: Mon Nov 30, 2020 9:12 pm There is no construction line in sketch.
Thats the point. The sketch shows as fully constrained, but as the construction line has disappeared. it should not be (the center oblong shape should be able to move).

But when I drew it I added a construction line between the outside and inside shapes, and did not delete it. It simply isn't showing
Bance
Veteran
Posts: 4186
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Construction line has disappeared (v0.19)

Post by Bance »

I don't know if you deleted it or not, all I can say is don't waste your time looking for something that isn't there!
garthn555
Posts: 6
Joined: Mon Nov 30, 2020 7:13 pm

Re: Construction line has disappeared (v0.19)

Post by garthn555 »

Bance wrote: Mon Nov 30, 2020 9:16 pm I don't know if you deleted it or not, all I can say is don't waste your time looking for something that isn't there!
But then why is the sketch fully constrained...that is contradictory. The reason I am trying to get it to display is that I need to lengthen it.

I'm already convinced this is a bug.
Bance
Veteran
Posts: 4186
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Construction line has disappeared (v0.19)

Post by Bance »

The sketch is fully constrained, one of the anomalies that can be found sometimes is that tangent constraints can cause lines to be fixed unintentionally.
See https://forum.freecadweb.org/viewtopic.php?f=3&t=52727.

Don't know if this should be considered as a bug or not.
abdullah wrote: Sun Nov 29, 2020 6:09 am
Bance
Veteran
Posts: 4186
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Construction line has disappeared (v0.19)

Post by Bance »

garthn555 wrote: Mon Nov 30, 2020 9:19 pm But then why is the sketch fully constrained...that is contradictory.
It's only contrary to your intention.

The solver see's it as a valid solution.
garthn555
Posts: 6
Joined: Mon Nov 30, 2020 7:13 pm

Re: Construction line has disappeared (v0.19)

Post by garthn555 »

Bance wrote: Mon Nov 30, 2020 9:29 pm
garthn555 wrote: Mon Nov 30, 2020 9:19 pm But then why is the sketch fully constrained...that is contradictory.
It's only contrary to your intention.

The solver see's it as a valid solution.
Then the solver is making an assumption that it should not. There is nothing showing on the sketch that constrains the middle shape from moving as a whole. After some fiddling I managed to unconstrain a piece of the shape, reconstrain it and then the whole middle COULD move. I was able to add the construction line (again) and set its length. Now if I delete the line, the solver immediately goes to one degree of freedom, as it should. If I put the line back and exit the sketcher, the line is there when I edit the sketch again
heda
Veteran
Posts: 1348
Joined: Sat Dec 12, 2015 5:49 pm

Re: Construction line has disappeared (v0.19)

Post by heda »

not that I know much about these things.
I could not even see the sketch in my v18, had to delete the parents or duplicate the sketch for it to show on the screen.

anyways, is this healthy, if they are removed the sketch is no longer fully constrained...
just a guess, could those 2 points be the construction line you are looking for?
maybe next time add the line in a picture, kind of hard to look for a line that is not there ;)
probably_not_healthy.png
probably_not_healthy.png (10.89 KiB) Viewed 621 times
Post Reply