How does FreeCAD choose the direction of angle constraints?

[esr]

Version 0.18.4, running under Pop!_OS 20.10.

When I create an angle constraint between two lines, the solver could use either of two complementary arcs - either clockwise or counterclockwise, with the recorded angles differing by complementation with 180 degrees.

I want it to use the arc that records the lesser angle, to make my spreadsheet with multiple angle constraints easier to read and reduce clutter in the sketch. Sometimes it chooses the greater angle (> 180 deg). I can't find any pattern to how it makes these choices, and the documentation is silent on this matter.

If someone can explain how this works, I will add it to the documentation wiki.

[chrisb]

I'm afraid that only Abdullah can answer this; and he cannot, because he is currently very busy. Let's ask him anyway:

ping

[drmacro]

You could have a look at his treatise, it may provide clues, but is specifically talking about the solver.

I converted to pdf so I could read on my tablet.

I have only gotten 7 pages in so far.

I've attached the pdf to this post.

[GeneFC]

Version 0.18.4, running under Pop!_OS 20.10.

There has been a huge amount of work on the sketcher in the past couple of years. In particular there has been a lot of work on constraints to make them more resistant to sketch-flipping and other problems.

Before pursuing this very far it would be a really good idea to update, at least to version 0.19, and even better to version 0.20

Gene

[esr]

Before pursuing this very far it would be a really good idea to update, at least to version 0.19, and even better to version 0.20

I hear you, but my one experience of trying to upgrade has been very negative. I tried to use the Aug 21st AppImage only to find that some bug had abolished the top toolbar. It was unusable - I had to use kill from another terminal window to get out of it. Then when I backed down to 0.18 . I found the AppImage had messed with my save in a way that made it unloadable.

Can you recommend a build of 0.20 that is stable and usable?

[GeneFC]

I have never heard of Pop!_OS 20.10, so I have no idea what might work.

A very large number of folks using all sorts of OS are working in version 0.20. It can certainly be done.

Gene

[chrisb]

You may upload a file with such a questionable angle. We could try in 0.20.
I haven't seen a flipping angle for quite some time.

[chrisb]

This is all I can come up with.

At the left the pair of lines was selected before creating the angle.
At the right the center was selected too.

[drmacro]

I run 0.20 very well on Debian 10 & 11 and UbuntuStudio 20 & 21.

Pop!_OS is an Ubuntu variant with a "custom" GNOME desktop, that appears to be only offered by System76.
(I have two Sys76 laptops...first thing I did was "pop" Pop!_OS and install UbuntuStudio. )

I'd guess it is a desktop manager "feature" that is clashing with Qt...note this is a WAG on my part.

[thomas-neemann]

.... clashing with Qt......

I agree. i am using xfce. that works without qt