# Mirroring a segment between points

When I try to mirror a segment, I’m grabbing two points (A6 and M2) and then flipping those points on an axis (the horizontal at CL). The points mirror to become A6a1 and M2a1, but the lines do not mirror; is there a way for me to get a mirror of the line that curves from A6 to CL so there is a mirrored curve going from A6a1 to CL (the theoretical red line in the screenshot). Note that line I want mirrored looks straight, but it’s actually a subtle curve belonging to a cubic bezier curve, and I would like the mirror to have the same subtle curve. I should also mention the “segment” between A6 and CL is not really a segment, because I have not figure out how to make it into one - right now it’s just a curve that point A6 happens to be sitting upon, somehow I need to tell Seamly2D that I want the curve from A6 to CL to become a segment.

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Eine Kurve spiegelt sich eine Linie nicht. Die Kurve musst du genauso anklicken wie die Punkte und dann spiegeln.

Ich habe hier eine Kurve mit zwei Punkten ( 96+97 ) um die Punkte 113und 112 gespiegelt.

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Selecting the curve does not create a mirrored curve. Also, I don’t want to mirror the entire curve, just the portion between A6 and CL.

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Die gespiegelte Kurve kann nur im Original verändert werden und das Original kann nur im Ganzen gespiegelt werden. Man kann aber mit der gespiegelten Kurve weiter arbeiten. In ihrem Fall müssen Sie die Kurve im gespiegeltem Zusatnd neu zeichnen.

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Yes, as @Scholli says, you can only select the whole curve.

To prevent this, I would suggest that you create a curve from A6 to A5 and then another curve from CL to A6. This way, you only need to select the bottom part of the curve between CL & A6.

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Lines have to be redrawn, curves can be mirrored. In your case, the Bézier curve is defined, redrawing a curve from CL to A6a1 would probably not yield the same result. In these cases I usually do one of the following:

1. mirror the entire curve, and then narrowing the curve portion when picking the nodes & curves for my pattern piece.
2. draw two curves with bezier „coordinates“ as if the adjoining end points of the two curves were the middle point of a 3-point curve (as Grace suggests). Kind of tough though, and doesn’t always work out. But maybe there are smarter ways out there.
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Here is the .val file where I did this. You will see that I used the 2nd handle angle of the top curve to create the 1st handle angle, just adding 180° to reverse the direction. By doing this, I am constraining the curve to follow the direction of the previous curve, for neatness.

Mirror curve.val (2.4 KB)

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I like using Bezier curves because they scale well when changing the measurements. Is there a chance we could get a tool that creates a segment between two points on a Bezier curve?

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Yes… Create 2 separate curves (splines are just a series of curves - see below). select mirror by line. Select the curve and the 2 points A3 & A2. Select the 2 points for the mirror line A5 & A4. Add a line between A3a1 and A2a1. It should be noted that “lines” in draft mode mean nothing in piece mode. They are only there in draft mode as a visual reference. Piece mode only works on point nodes and curves… it creates paths using the nodes and curves. A line is simply the (straight) path between 2 nodes.

That being said… would it be useful to be able to select lines for purposes of operations and piece selection? Perhaps. Off the top of my head it would most likely require some refactoring the line class as it lacks some of the sub class info that the rest of the tools have. Not sure why the choice was made to not make it the same as the rest of the tools, but [fill in blank]… water under the bridge, spillt milk, etc.

Just a note… they’re ALL bezier curves. The only difference is how the control points are defined. The Curve w/control points uses draft block points for the control points, where as the Curve tool uses user defined control points.“Splines” are just a series of consecutive curves. In theory we could really eliminate the curve tools as they are just the spline tools used once… or more specifically the spline tools more or less just repeat the curve tool until you press enter.

There is. Point along spline. If you want a point between for A1 & A2 along the SplPath_A6_2…Select the spline. Edit the formula to take the spline length of the 1st segment A6 to A1 and then add what ever distance from A1 to A2 you want. Here I used 1 inch to cretae point A7.

That being said… It’s always possible to add tools (as opposed to features) , the question is whether a tool is worth the effort. It takes a lot coding to add a new tool. If it doesn’t have wide appeal it’s not worth the time - at least not my time - to add it. I’d rather add tools or features that are really needed - such as support for symbols and buttonholes to name a few. Or maybe a “fold out” tool to create a hem on say a sleeve… which is what I think your original intention here is?

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