How to draw molecular biology cartoons?

Hello,

Could anyone advise how to draw something like this?

Or at least like this:

I need a way to draw a 3D "rope" wrapped around the eight spheres.

Are there some specific tricks to do this?

Thanks!

  • Don't think about it as a rope, but as pieces that give the illusion of a rope. Draw is a 2D programme, and therefore you should simulate depth. Use ellipses and boolean operators (trim, weld, intersect, etc) to give shape to your ropes. Use the images you just posted as a reference. 

    For the reflections on those ropes, I'd suggest blends, which go from the base colour of the rope to white or a light varian of that base colour.

    And no, there are no specific tricks. You just have to understand what the different tools can do and to be able to imagine how the finished piece should look like.

    • Thanks for the answer...

      But I have particular problems with the "rope", because when it is behind the "balls", you should not see it, right? So I am using curve segments for the parts of the "rope" that are not behind the balls. Do you mean that there is no easy way, and I have to compose the rope around each such object, of several curve segments? Then the problem is that their edges should ideally match, and it is not easy if the rope is thick (8 points in my case, so the curve edges become a problem).

      Another question is how to make a thick curve look like a 3D "rope". Is there a special techique for that? The curve can not be filled by a fountain color fill, that's my problem. Any ideas?

      • See if this will help. The rope is not continuous. I hand traced this. Took about 15 mins, cause I really don't kmow a lot of the tricks. The histone molecules are elispes with a power clip (black square with 3D noise created in PP)  in them and a white sphere with a  interactive transparency over them. Sloppy but it was done quickly.

        his.cdr
        • Thank you very much.

          I see, so my mistake was that I tried to draw the rope as a curve, while you did this as a more sophysticated object. But to do this, you really need to know how to draw (by hand). In the picture looks like hand-drawn. I mean, it's nice, but by doing this, it seems easier just to draw by hand and scan the picture from paper. I was thinking that there are some tools to 3D-deform an object, say, a cylinder representing the DNA...

           

          • corelfun1 said:

            Thank you very much.

            I see, so my mistake was that I tried to draw the rope as a curve, while you did this as a more sophysticated object. But to do this, you really need to know how to draw (by hand). In the picture looks like hand-drawn. I mean, it's nice, but by doing this, it seems easier just to draw by hand and scan the picture from paper. I was thinking that there are some tools to 3D-deform an object, say, a cylinder representing the DNA...

             

            I am an amateur, so don't rely on my answer alone.. It was only my approach. Others will be along, I am sure.

            • ...or 2D-deform the cylinder. I mean, to create a cylinder representing the DNA, and then deform it so that it has the same width. Otherwise, I would not be able to control the width of such a long and curved cylinder drawing it by hand.

              • "Use ellipses and boolean operators (trim, weld, intersect, etc) to give shape to your ropes."

                And how exactly to do this?

                • corelfun1 said:

                  "Use ellipses and boolean operators (trim, weld, intersect, etc) to give shape to your ropes."

                  And how exactly to do this?

                  Hi, CorelFun,

                  There's a docker called Transform. In this docker you can find the different Boolean operators. It's a matter of selecting an object or a pair of objects (depending on the operator you choose), ticking on the checkboxes as you find appropriate and hit the Apply button. Asides from your molecules drawing, try practicing with them, because they are VERY helpful for illustrating. Of course you could draw everything by hand, but they give quickness and precision.

                   

                  corelfun1 said:
                  The curve can not be filled by a fountain color fill, that's my problem. Any ideas?

                  Any curve can be filled, as long as it is closed. If you mean the LINES, then convert them to curves by selecting them and pressing CTRL + SHIFT + Q. Then you can treat it like a normal curve, although there's no revert command: once an outline has been converted, it will always stay a curve (that means: no more changing its parameters via the Outline commands)