Hypothetical: You have a single line, an open-ended path, with only points. Both points have bezier handles.
How does one extend that arcing line further so that it extends without changing the existing curve?
I've faced this many times. Each time I just get as close as possible by drawing a new shape under the line in question. But is there a lossless method?
Sorry for not being specific enough.
No, I'm trying to continue a curved line using it's established curving path. Does that make sense?
In other words, in your simple example the circles would be completed, since if the method returned the right result you would have lines that continue going the curving direction.
Maybe it's not even possible. I'm not sure.
In your included example though, did you use an exact method to determine the angle of your blue lines or is that just eyeballing?
In the example above I used a graphic style (consisting of a Pattern brush) to extend according to tangents.
But that's not what you want, and as AI still does not offer live shapes the way you're looking for, you cannot do that currently.
Someone else may suggest to buy a plugin to get that feature.
Do you by any chance know how to make a curve rounder? I'm looking at this tutorial http://blog.spoongraphics.co.uk/tutorials/fun-vector-monster-character -illustrator-tutorial I'm totally new to Illustrator and it took me like half an hour figuring out that you had to click alt or something to change the type of rectangle. I need to know how to make the curve rounder as is in the link.
You have to be a bit more specific, Leonardo: The monster is primarily created using Rounded Rectangles, and they get no rounder than with the Radius being half the width/height, whichever is smaller.
Basically you just click on an open end with the Pen tool, drag without moving the existing curve and then click to define the next anchor. Where you click is your decision.
If it is absolutely imperative that the existing arc does not move at all, it’s not a bad idea to drag ruler guides to the end of the handle to mark the spot.
You are welcome, Leonardo.
If you wish to extend a path ending in a smooth Anchor Point, in other words one with Handles, the direction(s) of which represent the tangent, and if you wish to make sure that the extension accurately follows the tangent/Handle direction, you may use this rather silly way (Smart Guides are your friends):
1) Select the end Anchor Point with the Direct Selection Tool,
2a) With the Pen Tool click the Handle (Smart Guides say handle) and click the Anchor Point (Smart Guides say anchor), or
2b) With the Line Tool drag from the Handle (Smart Guides say handle) to the Anchor Point (Smart Guides say anchor), then drag over the end Anchor Points with the Direct Selection Tool and Ctrl/Cmd+J to join, using Smooth.
2a) is simpler, but it will reverse the direction of the path if done with the last end Anchor Point (lastly), hence the even sillier 2b).
There may be less silly ways to make sure, possibly in the newer/newest version(s).