Sketcher Constraints checkbox -- What does it do?

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chrisb
Posts: 25745
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketcher Constraints checkbox -- What does it do?

Postby chrisb » Sat May 23, 2020 9:18 pm

garya wrote:
Sat May 23, 2020 4:42 pm
@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.
Is it possible that you used undo? I had been looking for an error and finally could reproduce it, see https://forum.freecadweb.org/viewtopic.php?f=3&t=46419. Werner has already fixed it. Please retest as soon as you get the updated version.
garya
Posts: 221
Joined: Tue Nov 20, 2018 1:00 am
Location: Ovando, MT, USA

Re: Sketcher Constraints checkbox -- What does it do?

Postby garya » Sat May 23, 2020 11:35 pm

chrisb wrote:
Sat May 23, 2020 9:18 pm
Is it possible that you used undo? I had been looking for an error and finally could reproduce it, see https://forum.freecadweb.org/viewtopic.php?f=3&t=46419. Werner has already fixed it. Please retest as soon as you get the updated version.
Just saw that. I probably used undo somewhere in there. I've been trying to pay a little closer attention to what I'm doing to see if I can reproduce it. One other thing I've run into but haven't been able to reproduce is a disconnect of constraints tieing the origin of an arc to the origin of the sketch -- I delete some lines and constraints, add in new ones, and then notice arcs which haven't been touched can be moved, even though their radius is set and their endpoints are again tied to other fully-constrained parts of the sketch. On closer inspection I can see their center is floating.

I'll see if I can build a new version and keep an eye out for any oddities.
chrisb
Posts: 25745
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketcher Constraints checkbox -- What does it do?

Postby chrisb » Sun May 24, 2020 6:43 am

If the solver reports an error, e.g. redundant constraints, then subsequently added constraints are not shown correctly until you remove the error. So if you have such an error and after that you add a circle, starting with autoconstraints and you make the centers coincident, they well can show different positions.
garya
Posts: 221
Joined: Tue Nov 20, 2018 1:00 am
Location: Ovando, MT, USA

Re: Sketcher Constraints checkbox -- What does it do?

Postby garya » Sun May 24, 2020 3:05 pm

chrisb wrote:
Sun May 24, 2020 6:43 am
If the solver reports an error, e.g. redundant constraints, then subsequently added constraints are not shown correctly until you remove the error. So if you have such an error and after that you add a circle, starting with autoconstraints and you make the centers coincident, they well can show different positions.
In this case there may have been earlier errors; if so, they were all corrected. I can't remember if there were actual errors or just insufficient constraints as a result of removing some lines and then adding new ones. No arcs were added in, just straight lines. The sketch would have been fully constrained if the centers of the arcs hadn't been disconnected from the origin. Once they were manually re-made coincident with the origin, the sketch was fully constrained.
Still trying to build with the new version; having some python version issues.