19

line frame 1 line frame 2

I love and have always been mystified by this kind of swirly design.

After +10yrs working as a graphic designer, I still can't wrap my head around how those are done. Geometric curved design in general.

How do they connect their different parts so seamlessly? It can't be a single piece made by hand as in placing every point and fine-tuning every bézier handle, it's too perfect, too geometric to having been done that way.

Has any of you worked on this technique on Illustrator? What is the approach?

  • Why do you need to let us know you have 10+ years as a designer? Just curious what benefit it adds to the question. – DᴀʀᴛʜVᴀᴅᴇʀ May 30 '16 at 18:28
  • They were...drawn that way? Not sure how to answer this. They are segments of curves joined together. Same concept as using french curves pre-computer. – DA01 May 30 '16 at 18:39
  • @DA01 Well see people under the age of 30 might not ever have seen french curves or drawn on paper with rulers and compasses. Just saying. – joojaa May 30 '16 at 19:42
  • 1
    @joojaa eh....yea, well...OK, I see your point. But would argue anyone that's a graphic designer should have. It's like an architect not knowing what a architects ruler is. Yea, they don't necessarily use it but it comes with the turf/history of the profession. :) – DA01 May 30 '16 at 20:36
  • @DA01 You will find that often people do know lots of things they are just unable to combine this knowlege to a whole and apply it in specific cases. So should is one thing, but if one does not then even more important to explain it. All in can say is i tought it would be self evident that a 4th year master student in mechanical engineering would know trigonometry. Apparently a good third of them do not, not really. But yes i had a similar knee jerk reaction. – joojaa May 30 '16 at 20:58
24

There are many ways of approaching this. You're right, a curve does not have to be made out of one piece, it can be built out of several pieces. In fact one curve can be built out of several curves.

I have answered a similar question, about spiral caps, mostly the same applies here. When you do is you make a initial shape and then rotate and mirror it about. The later picture is a great example of this. Curves can be built using 2 adjoining arcs for example. Also might be a liberal reuse of a single drawn path, offsets, mirror and cuts by circles and lines.

Second the construction piece can be built out of a different function than a spiral. Although snapping with a manually constructed grid achieves similar precision of line. Again the trick is to mirror and rotate the symmetrical parts and line segments.

construction of a loop

Image 1: Construction of repeatable pattern

Doing accurate work in Illustrator depends on the mastery of Line tool, Ellipse tool, Rotate Tool, Mirror Tool, Scale Tool and Skew Tool. Of these the most tricky one to master is the line tool as mastery of it and ellipse tool depends on you knowing how to use the alt click dialog. And for line tool there are 2 reasons to do this!

custom construction guides by offset

Image 2: Make custom construction guides and you can cut and attach them to your heart's content.

How it's made (tutorial, as per request)

To answer the comment on how it's made, I will outline the process of making Image 1.

  1. Drawing your primary guides.

    • Start by drawing an oval and a small line segment at the middle of the oval. The line is there so I can more easily snap to the rotation center (at end of line)

      enter image description here

      Image 3: Remember to mark your rotation center, it's easier this way

    • Use rotate tool to rotate the guide, in this case 90 degrees but you could use any other angle. Tip: Alt + Click will place pivot and open a dialog for numeric input.

      Strictly speaking one does not need the third and fourth guide but since the repetition is just a keystroke away I make then nonetheless, it gives me a better idea of what the size is going to be. Adjust the guides now to fit your need.

      enter image description here

      Image 4: Take your time making the guides.

    • You need to prepare to cut the ovals in on their intersections and after (or at) the curve starts to dip down towards the mirror line. For this I prepare a perpendicular cut line and a mirror line.

      enter image description here

      Image 5: Prepare the cut lines

    • Copy one of the ovals and make a new layer, paste the oval in front. Lock the guide layer.

  2. Constructing the shape.

    • Remove the lower half of the oval.

    • Insert a point at the first intersection of oval and cut the oval into 2 at the oval to oval intersection.

      enter image description here

      Image 6: Cut in pieces

    • Mirror a copy of the segment over the mirror line and join the curves. Tip: if Illustrator inserts a span in between just move one point to the side delete span, move back and redo the join, the curves are now pointing the same way and there will be no extra span.

      enter image description here

      Image 6: Join to mirror

    • Use convert anchor point tool to make the corner end a unified tangent. Drag the tangent perpendicular to the mirror line. Tip If you work in awkward angle you can measure the angle with line tool and use the prefs to rotate your grid.

      Make the tangent slight shorter than the width of your gap at nearest points (or equally wide). One can adjust how round the edge is by making a longer tangent. I'm making the shape a bit more pointed than in the original example to show one can vary the shape freely.

      enter image description here

      Image 7 Make the tangent symmetrical and perpendicular to mirror line

    • Drag the curve point back along the symmetry line until you have nice asymptotic behavior.

      enter image description here

      Image 8 Adjust loop.

    • Hide guides and mirror/rotate and join.

      enter image description here

      Image 9 Final image.

Post scriptum

After all that work I would like to say that graphing the function:

x=20*cos(t)-10*sin(5*t+PI/2)
Y=20*sin(t)+10*cos(5*t+PI/2)

Would yield:

enter image description here

Many ways to skin the cat I guess.

  • Great answer, thank you! I still would love to see a bit of a deeper insight in the technique, with a step by step reproduction of some of the shapes I posted, very very curious about some of them and what kind of workflow (which booleans to use, tool techniques, etc) does it take. But that's asking too much. Thanks again for a nice post. The one about spiral caps helps as well. – MrMerrick May 30 '16 at 12:54
  • @MrMerrick Done – joojaa May 30 '16 at 17:43
  • Many thanks for taking the time and effort to answer @joojaa. Missing puzzle piece for me was using those helper symmetry lines where I can snap points along them in order to refine the shapes. I'm used to working with mirrored stuff to create geometric artwork, but when it comes to curves and more flowing work I had trouble making it look smooth. I'll invest time taming that arc tool. May I ask 2 final questions? 1- what do you mean with the line tool mastery? I only use alt to either make it grow on the opposite direction of its origin or alt + clicking to get the create dialog. Is that it? – MrMerrick May 31 '16 at 7:08
  • and 2- On your figure 2, how do you make those wavy lines so awfully smooth? Is that simply arc tool or is it actually point-by-point constrained (holding shift while placing and dragging the points) bézier? This is the farthest I got with the arc tool + blend, which is ridiculous. – MrMerrick May 31 '16 at 7:16
  • @MrMerrick its a single span bezier. Anyway do not use the arc tool its useless. Same uselessness applies to all the other shape tools except spiral, line and ellipse. Even so the ellipse tool is less than optimal. New illustrator also has a new curve tool that is better than beziers. B-splines and spirocurves just are superior. – joojaa May 31 '16 at 8:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.