Create a double helix

Forum|Forum|8 years ago
June 7, 2017
3 replies
6120 views

One would think a double helix wouldn't be rocket science in Illustrator, but I'm stumped. See the two twisted ribbons herewith, each created by extending a thin rectangle diagonally along the extrusion of a circle, using 3D effect. I'd like them to twist inside each other, though. I don't need the final illustration to be editable 3d, though that would be cool. The first blunt-object idea I had was just to expand/flatten the top object and then erase the portion that's going "behind" the bottom object. This has proven more difficult than I'd hoped.

Any help doing this, or finding any other nifty way of making a double helix in Illustrator gratefully accepted. A google search has been surprisingly unsuccessful.

Rob

double helix

Correct answer Mike_Gondek10189183

Here is my 2D live effects interpretation in case this is useful to you.

http://files.kaleidoscopechicago.com/_2Y0KqXd7vTXs9R

Double Helix.ai

1.1 MB

The URL will expire on July 7.

kphotopage

Legend

I did something similar. I am sharing if interested.

My starting point was an angled stroke line and applied a Warp>Flag.

Expanded the Flag.

My friends here were Selection Tool, Direct Selection Tool, Layers, Transform, Align, Pathfinders, Preview Mode, Outline Mode, Smart Guides, Live Paint.

I then made some Pattern Brushes.

K

Mike_Gondek10189183

Correct answer

Community Expert

Here is my 2D live effects interpretation in case this is useful to you.

http://files.kaleidoscopechicago.com/_2Y0KqXd7vTXs9R

Double Helix.ai

1.1 MB

The URL will expire on July 7.

R

Rob EhleAuthor

Known Participant

This is really elegant, Mike. Thanks.

I also found this older discussion where JETalmage uploaded a really interesting PDF showing a 3D effects approach. The downside to that, at least the way I worked with my own file, is that the file was 31 mb, and after awhile, at least on my computer, the slightest modification causes a really slow redraw.

I'm thinking, though, of doing an Expand Appearance on the "twisted ladder" and then adding on your ribbons for a complete DNA strand.

Mike_Gondek10189183

Community Expert

Great glad you enjoyed that. Please post your result if you have time and let us know what you might find. If I had time was going to make a new stroke profile where the center is not as fat so the tips do not get so thin.