How Do You Make Two Lines Have the Same Curvature in Affinity Designer?

[Scout_Fox]

Hey all, hope you are doing great and that it is a beautiful day out. Had a questions about something I find myself doing quite often but haven't developed a good process for. I have attached an image of what I am trying to describe.

So, often what I'm trying to do is create a custom sized shape where both sides follow the same curvature by using the pen tool. Since the curvature is determined by the control handles (both the desired ones are selected here, everything else is sharp point) I have never been able to see how to make the curve amounts the same. Is there a better way to do this? Is there some step here I am missing?

Thanks for any help you can offer.

[ESPR]

You can draw it as a single stroke with enough width, then expand and remove the top and bottom bits and give your new parallel strokes the desired width.

[PixelPest]

1 hour ago, ESPR said:

You can draw it as a single stroke with enough width,

That will just work with straight lines.

I´d try this method:

[ESPR]

33 minutes ago, PixelPest said:

That will just work with straight lines.

What do you mean with straight lines ?

 

Maybe im misunderstanding the problem, but in a ring, the two circles forming the ringshape have different diameters/circumference.

You cant recreate that by duplicating one of the rings.

[PixelPest]

I´m in the same boat; is it about curvature or parallelism?

[Pšenda]

2 hours ago, ESPR said:

in a ring, the two circles forming the ringshape have different diameters/circumference.

And that's why they have different curvatures.

[Scout_Fox]

Thanks for all the help!

7 hours ago, PixelPest said:

I´m in the same boat; is it about curvature or parallelism?

The curvature when I'm trying to create a shape where the inner ring doesn't have as great a circumference as the outer ring. @PixelPest in the gif example (thx btw) you gave earlier, that makes sense when both the outer and inner ring are the same size and you are creating something with parallel lines on top and bottom. However generally what I was trying to do was create something that pulled towards the center where, as @ESPR pointed out,

7 hours ago, ESPR said:

Maybe im misunderstanding the problem, but in a ring, the two circles forming the ringshape have different diameters/circumference.

You cant recreate that by duplicating one of the rings.

And that was what had always been my problem. In duplicating and trying to minimize the circumference (so that the ends taper in instead of being parallel) I always changed the curvature.

 

What I hadn't thought of that ESPR pointed out first (and PixelPest you put in one of your screenshot examples) was this

8 hours ago, ESPR said:

You can draw it as a single stroke with enough width, then expand

This creates a ring with both sides having the same curvature but the inner one being at a lesser circumference (so that the top and bottom taper in) and was exactly what I was looking for. In fact I really don't even need to expand it, I only needed a blocky shape so the overexagerated line works fine.

Thanks everyone! Had been bothering me for a while now and you all gave quite prompt and helpful answers (allthough my reply time could be improved lol).

 

 

Oh and:

5 hours ago, Pšenda said:

7 hours ago, ESPR said:

in a ring, the two circles forming the ringshape have different diameters/circumference.

And that's why they have different curvatures.

Yes. I was more thinking along the line of the same ratio of curvature. The inner and outer rings may curve different amounts but using the examples given above you can make it so that they are proportional. Like if you cut out a piece of pie and then only used the crust, that shape was what I was looking for. The inner and outer parts have different circumferences but a proportional amount of curve so they look cohesive.

Edited August 10, 2020 by Scout_Fox
Better quotemanship

[Pšenda]

Try Pie Tool

https://affinity.help/designer/English.lproj/pages/Tools/tools_pie.html

[Scout_Fox]

54 minutes ago, Pšenda said:

Try Pie Tool

https://affinity.help/designer/English.lproj/pages/Tools/tools_pie.html

oh... huh... had never even noticed that before. I think if I just keep reiterating you guys will make it so easy it'll do itself lol. That works perfectly as well. Thanks everyone!

[PixelPest]

At no time have I read anything about partial circles. The title demands something else I find. 🥰

[Scout_Fox]

20 minutes ago, PixelPest said:

At no time have I read anything about partial circles. The title demands something else I find. 🥰

I would tend to agree! Both methods are actually what I'm looking for, just for different use cases. The over-thickened single line was useful on something that required a non-perfect circle but still a ringish shape that had proportionally curved edges, the pie tool has been useful on a different project that required pieces of a perfect circle. I think I merely hadn't thought it through enough to think about using the tools like that. Better title suggestion?