Sketecher Mirror Bug

[mario.silva.costa]

Hi,

I've performed a complex scketch, and after I've applied the mirror scketch operation across x axis. The result has a bug, on some parts. Check the image below.

OS: Ubuntu 16.04.2 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.11580 (Git)
Build type: None
Branch: master
Hash: aa07c777453258edf9fed304cf82bcfeb8bdea95
Python version: 2.7.12
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.1.0

If more help is required to reproduce, let-me know.

Cheers,
mc

[cox]

If more help is required to reproduce, let-me know.

More info is always better, if you have it provide it! Your project file would help anyone wanting to figure this out.

[chrisb]

I've performed a complex scketch

Not knowing what you want to do with the sketch I may give a preliminary warning: The sketch has self intersections, thus it may be impossible to be used for padding or pocketing.

[mario.silva.costa]

Its a template for a cardbox. Not for pocketing or padding. Will convert it into a drawing.

The constraint system of freecad is realy nice for many things!

Please check the simple example attached, so you can use for testing, It does shoes some issues with mirroring the sketch, strangely more than those I mentioned.

freecad_error_mirror_sketch_op.png (3.84 KiB) Viewed 1080 times

OS: Ubuntu 16.04.2 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.11580 (Git)
Build type: None
Branch: master
Hash: aa07c777453258edf9fed304cf82bcfeb8bdea95
Python version: 2.7.12
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.1.0

[chrisb]

There seems to be in fact a bug in the copy mechanism of the constraints. While the horizontal and vertical constraints are not mirrored, the distance/lineLength distance is. Point-on-line is not mirrored.
A general problem might be that the constraints don't define a unique sketch. In the case given here there are different sketches conforming to the constraints.
Please note, that "fully constrained" means that the number of possibilities is finite, but not 1.