We can draw a number of curve and use FPolyCurve to fuse them into a "smooth" curve. An old post has discussed this question here. However, my model required a 2D "not smooth" enclosed curve made with three curves as below.
It requires more than 2 intermediate points, therefore we can't use Multi Segmented Smooth Curve. And it's not a "smooth curve" therefore we abandoned the 2D interpolation curve. Therefore, I used poly curve, and results looks like this.
To zoom in, we found flaws at corners.
This flaws blocks me from moving forward in modeling. Get rid of the top line and the polyCurve seems work normal. My guess for the cause of the problem is the discontinuity, not a jump point but a removable discontinuous point.
Please let me know if there is a way to deal with non-smooth multi-segmented curves. Any inputs are appreciated!
WX