abdullah, thanks a lot for your kind introduction into the issue tracking system used by FreeCAD developers. It's more complicated than what I'm used to... I hope this will be helpful not only for me.

Au contraire, solver stability is well taken into account in the overall discussion. This kind of bug reports help me to have a broad view of the possible edges. The broad view has resulted in a package of improvements that has just been merged. I really hope you will find a better overall behaviou...

Thanks for fixing the most often occurrence where the bug is exhibited!

What bothers me is that neither the very bug nor unstable behaviour of the solver have not got any attention in the discussions... These definitely will continue to show up...

Sorry for my pessimism and thanks for your work.

The attached Python script shows what I think is a bug in FreeCAD. The script can be run as FreeCAD path/to/file.py or as a macro, if correctly placed and named. What it does: Creates a new document. Creates a cube shape of default size 10x10x10. Makes a mesh from the shape. Iterates over the points...

Python in FreeCAD supports the creation of a solid out of its faces. import Part myShell = Part.Shell(listOfFaces) mySolid =Part.Solid(myShell) Part.show(mySolid) In your case I would write a script that creates your top face based on the Z(x,y)-function and create the missing side faces and the gr...

IMNSHO if (1) a message 'redundant constraints' is shown, (2) an edge tangent constraint is used, and (3) a coincident constraint is used, then a longer explanation can be added to the message. Something like "Edge Tangent + Coincident combination causes solver instability. When possible, use E...

chrisb: Thank you for your tip. NURBS is a good stuff. It's intended for defining surfaces in a special way, simpler in use and often fast and efficient (I did use some splines in different systems, so I know the power of the approach). But I have already a definition of a surface as a function of t...

I need some help (pointers to docs, examples or discussions, an advice) for how to use a function Z(x, y) as a face of a 3d part. I have a function written in Python. I can build a body by defining a sketch in XY plane and padding it. Now I need to change the top face to have at each (x, y) point a ...

The sketch in question contains tangent connection made by Tangent + Coincident constraint combination. This is very likely the cause of unstable behavior. Such combination is bad for solver, and should be replaced with tangent applied to endpoints (and no need for coincident). IMHO known combinati...