4-bar hinge and 5-bar hinge will be more stable.
But the making such a mechanism seems difficult. So I chose the 3-bar hinge.
Bars 1 and 2 must always form an isosceles triangle. For example, when the bar 1 increases by 30, the bar 2 becomes (-)60, and when the bar 1 increases by 60, the bar 2 becomes (-)120. The sum of the three angles is 180 degrees. So, Bar 1 and bar 2 joing with bar 3 at the same angle. The arithmetic I learned in elementary school helped me just now. But not all 3-bar hinges are. This way is easy for rigging with Poser.
This is able to fold up properly.
I lined up a lot of this.
The top and bottom are paired.
Of course these are for opening and closing windows.
A bay window is. This is not very elegant. But I’m generally satisfy with this.
As usual this is too big for Pranx. But may be a little small for La Femme. I tend to forget that she is about 5.9 feet tall.