Status of FreeCAD 0.19

[triplus]

We have discussed the length constraint in the past and the conclusion was it would be difficult. Hence likely not something for targeting FreeCAD 0.19. As far as Sketcher in FreeCAD 0.19 is concerned best to focus only on (oppressing) issues, if any.

[-alex-]

I have been away for quite a while, and I do not find easily any thread relating to the release status.

Glad to see you back, wish you the best to you and your familly.
Thank you for your great job about Freecad

I was wondering....Is there any Sketcher showstopper?

I thought about a kind of issue concerning the reversing of line elements when modifing too much a constrain of distance.
Maybe it's already known, but i wasn't able to find bug report or topic about this.
Below a short video to show the behaviour:

sketcher_reverse_line_element.gif (94.9 KiB) Viewed 969 times

In this case there is no reversing for a variation from 10 to 28mm, then the reversing occures from 10 to 29mm and more.
This behaviour involves unstability concerning PartDesign models with dependancies between sketches, because it can create some reversion in other skteches with Xref. New and unexpected faces are generated on the model, hence it involves a new toponaming then the model fails.

[*]grey lines for construction lines is not optimal. Did you think about making dashed lines ? Would be cool

+1
construction dashed lines would be great to get entities selectable outside the sketch (when visible), and more visible for ones who have color vision troubles.

[triplus]

This was discussed on multiple occasions in the past couple of years. There is currently no known solution, when changing the value from outside of the Sketcher edit mode. From inside of the Sketcher edit mode, using Levenberg-Marquardt solver improves the situation:

https://forum.freecadweb.org/viewtopic. ... =30#p92119

P.S. That is usually you don't need to use the "incremental approach", for changing the value, and to prevent the flip to happen.

[-alex-]

using Levenberg-Marquardt solver improves the situation:

Thank you, following your information I have activated the "show section 'Advanced solver control' in task dialog" parameter in Preference-> sketcher -> Sketcher solver section.
Then I've selected Levenberg-Marquardt as default solver in the skecther task panel when editing the sketch.
Works like a charme

[triplus]

You're welcome and note that i added a small remark here:

https://forum.freecadweb.org/viewtopic. ... 12#p376612

[-alex-]

i added a small remark here:

that's the place to be indeed, perfect
I'm not aware about the advantages/drawbacks of each solvers, but IMHO Levenberg-Marquardt as default solver makes sens. Prevent flip of lines is a huge advantage for the model stability.
In addition when the topological algorithm will be merge the modeling stability should reach a high level and reveal the real skills of Partdesign WB.

[chrisb]

There is a good chance to improve this, but I guess this would be a major change. Currently the orientation of the lines is only for angles taken into account. If this could be augmented to other constraints as well, then flipping of sketches could be avoided in many cases.

[triplus]

Is there something major where work is necessary? Is there any Sketcher showstopper?

I guess we have a candidate:

https://tracker.freecadweb.org/view.php?id=3658

If some amount of progress or at least understanding could come out of it it i guess it makes sense to discuss this a bit further.

Reference.
https://forum.freecadweb.org/viewtopic.php?f=8&t=44312

[triplus]

how difficult would it be to implement "length of curve" as dimension/constraint ? Let's say I have 3 tangent lines and I'd want that their combined length be constrained. Or, if not for an entire combination of lines at least for an arc : yes, I know I can do it by calculations, but it would be useful to have it as a constraint. The use-case is if you have a bending plate, the neutral fiber – that we approximate with an arc – will remain constant and the radius and angle of the arc adjust as necessary. I use that a lot.

https://forum.freecadweb.org/viewtopic. ... 20#p380393