Since your two vertical lines have an equal length constraint, you don't even need to add a symmetry constraint. Add coincident constraints between the arc's endpoints and the vertical lines. The arc centre will automatically be centred between the two lines.
I said exactly why I thought it was not fitting the description, if you wish to disagree, please be more specific than basically saying "yes it is".For me it works exactly as the tooltip says.
What you're saying does not make sense. If choosing a point as symmetry axis, how exactly is it supposed to infer your intent? Here's one very handy use of the symmetry constraint: centre a rectangle on the sketch origin point. You select two diagonally opposed points on the rectangle, then select the sketch origin point, then apply the symmetry. With what you are proposing, I would need to add yet another constraint because it would lock the symmetry in only one axis.freman wrote: ↑Tue Dec 25, 2018 6:27 amTo apply symmetry as claimed it needs to draw a line between the two points find the perpendicular to the reference point and constrain the intersection to bisect the line between the two points. If the aim of this tool is to make all three points co-linear, then this should be clearly stated in the hint.
Perhaps the word "or" is the cause of the troubles. As you probably know there are several notions of symmetry. FreeCAD symmetry implements two of them. I am not a native english speaker and since this topic is much about words I follow the wikipedia notions from https://en.wikipedia.org/wiki/Symmetry#In_mathematics.
Your text is in fact more precise, but for me the hover text is only a short reminder, it does not hold the whole documentation. So I would rather suggest "Create a symmetry constraint".freman wrote: ↑Tue Dec 25, 2018 11:15 am"Create a symmetry constraint between two points with respect to a line or a third point (S)"
I think I now know enough to suggest a better hover hint text:
"Create a symmetry constraint between two points: a reflectional symmetry with respect to a line or a rotational symmetry about a third point. "
If you want to show the macro text: put the text in code tags </>.PS how do I make that macro visible in line? I clicked "place inline" and I just got two links
Indeed, one needs to avoid cluttering the UI. However, I don't go with dumbing down the user. The hint I suggested is enough to make him aware that there is a difference and if that is not meaningful he needs to look into it. Leaving him blind will head to confusion.Talking about two different symmetry operations and icons we should consider usability as well. It is easy and unique to distinguish between the symmetry variants so that most users don't even realize that these are two different mathematical things.