How might I go about making a cartoon DNA double helix? Thanks.

Hmm, there's two ways I can think of to make double-helixes (but I don't know much about making 'em look like a cartoon)

One would be to make two paths that act like the walls of the helix and then use the SubPath Stitching Path Effect (which will build the "stairs"). Although this might not work too well for a cartoony effect (but it would make a good base to use as a skeleton of sorts and draw a double-helix over it). For more info on using SubPath Stitching, visit http://www.inkscapeforum.com/viewtopic.php?f=5&t=446&p=2922

The other technique would be to use tiled clones. (You'll need to experiment with it, but I'm pretty sure it can create the "stairs" of the double helix). Here's a useful tutorial for using tiled clones http://inkscape.teekoo.com/index.php?select=bar

I also don't know how to make it cartoony. But you might also experiment with this technique using the Spiral tool .

Make a spiral with whatever variables you need.
Object to Path.
"Rubberband select" ALL the nodes.
Hold down the Alt key.
Grab either end of the spiral with the mouse.
Drag it out.

Note that using the default spiral tool settings, this creates a gradually tightening helix. But if you change the Spiral settings so that you start with something like this, then the helix looks more normal. Also note that after you do Object to Path, you can't change the Spiral settings.


Good luck

I would probably draw it as you see it. If the ladder needs to bend I would draw a section then use it with Pattern along path.

Hi everyone. I was thinking alone the lines of this: http://homepage.mac.com/grhowes/Blog/double_helix.pdf

The spiral effect doesn't really work 'cause when I stretch it out, it doesn't stretch evenly and the stitching may be a useful effect to join the strands into "base-pairs" but doesn't help with creating the backbone.

Could you use one full loop of the Spiral-made helix for a Pattern or Tiled Clone?

I don't know much about the Pattern along Path, but have played around with Tiled Clones some. I think you could define one full loop of the spiral-made helix, for the original tile, and it would be a simple translation, one row or one column, depending on how you want to set up the original tile. Then the helix would be identical, literally, for as long as you want to make it. Right?

I'll try to make a sample.

[Edit -- Ok, how long of a helix do you need -- how many loops? Because using the Divergence setting on the spiral, you can squeeze many, many loops into a tiny area. So that setting it to 30 Turns, I can get about 8 loops that look relatively equal. I'm just thinking maybe for a cartoon, you don't need a big long one? Anyway, I'll have a couple of samples ready before too long. Brynn]

[Edit #2 -- Once I figure out how to make a fairly consistent serires of loops with the Spiral tool, I dropped the idea of using Tiled Clones. Although I still think it could be done. Anyway here's what I got. Nothing fancy, but is this kind of what you're looking for?

seans_potato_biz wrote:Hi everyone. I was thinking alone the lines of this: http://homepage.mac.com/grhowes/Blog/double_helix.pdf

With this example, I would do as I suggested and draw the most basic element of that image and repeat it. I'm happy to provide an example but I don't have time at the moment. I'll try not to forget to create it when I get a chance.

Try this: Make a rectangle (not rounded) that is about 10 times a wide as high, Path->Object to path; Adjust the nodes : There should be four, make the upper left a corner node, the lower left a smooth node, the upper right smooth, the lower right corner; Then fiddle with the nodes: The upper left goes higher, the lower right lower. the sides should begin vertical, the smooth nodes should be adjusted so the thickness of the "rectangle" stays uniform, apart from the tapering ends of course.

Now copy it, and flip the copy upside down & give it another fill color. align those two, so the drooping end and the sweeping-up end meet. now you have one "turn" of the DNA.

Copy -> Paste; Now you got double stranded DNA, ready to roll.

Like so: .

loonquawl wrote:Try this: Make a rectangle (not rounded) that is about 10 times a wide as high, Path->Object to path; Adjust the nodes : There should be four, make the upper left a corner node, the lower left a smooth node, the upper right smooth, the lower right corner; Then fiddle with the nodes: The upper left goes higher, the lower right lower. the sides should begin vertical, the smooth nodes should be adjusted so the thickness of the "rectangle" stays uniform, apart from the tapering ends of course.

Now copy it, and flip the copy upside down & give it another fill color. align those two, so the drooping end and the sweeping-up end meet. now you have one "turn" of the DNA.

Copy -> Paste; Now you got double stranded DNA, ready to roll.

Like so: .

This one is pretty swish, especially when used as a pattern to follow a path. Thanks for the suggestions, everyone.