Thursday, October 18, 2012


Want to make a nice lumpy bean pod.  So obviously I need to start with a scaleable curve & use alternating profiles.

The first attempt was pretty awful ... get rid of the sharp corners.

That seems to be working, let's try a longer section.  Now hosting lots of profiles on a curve can become tedious: first place points, then make their workplanes visible, then set current workplane, place profle, set workplane, place profile.  But working on Mr Bean I made a discovery.  Select point & profile, copy them into empty space, they remain associated.  So use multiple copy to make a whole bunch: click, click, click.  Now you can rehost the points on the curve.  Select, rehost, select, rehost ... nice !

So with a bit of adjusting of profile sizes I can make a fairly convincing bean pod.  It will scale up and if I alter the ratio of length to width it will become straighter or more curved.  I can make a collection of pods that exhibit natural variation in size and shape, all from the same family.

So far so good, but I'm starting to think these would make nice witch's fingers.  I made the family flat on the "floor" so if I want fingers that radiate out in a natural way I will need to associate each one with a separate vertical reference plane.  That's too messy for me, so let's start afresh with a vertical rig.

But first I'm going to adapt the profile so it works for both types.

It turned out that I can do that in the traditional family editor way with reference planes.  Place points at the intersections and they will move with the planes.  Spline by point finishes the job.  I rig up the parameters with simple formulae so that in the host family I can just adjust W (width) and F, which is a factor controlling whether it's a lump of a flat part.  0.7 gives a lump, 0.2 makes it flat.

The rig is simple enough & I used the "point copying" trick again to speed up the hosting.
Select all the profiles plus the spline and create form. 

Apply material parameter, let's give it a bump map too. 

Now I can paste a bunch of these in my project, move and rotate them at will, adjust length and width ... it's a hand !   Suitably green & ghoulish for halloween methinks.

Change of tack.  What if I convert this rig into a closed profile and add a rotation axis.  While it produce a nice scaleable form ?  Maybe a pear shape ?
It was easy enough to adjust the spline curve, close it, and add another reference line to act as an axis. 

Select the closed curve and the axis, create form, & it works.  Adjusting the rotation start and end angles gives me half a pear.  Fine.  So add another profile within the same rig, revolve this and very soon we have a scaleable avocado. 

If you want to vary the shape as well as the size, you could parameterise some of the ... values.  Or you could just create 2 or 3 families with different names and adjust the points manually in family editor.  As for me, I decided to call it a day.



  1. Now THAT is biomimicry!

  2. Once again. Fantastic. BTW, I just discovered that little rehosting trick too... we seem to be on parallel paths...

  3. Hi Andy! Your vegetables are making me hungry!
    Btw instead of copying and rehosting, have you tried selecting the hosted point and profile, then hitting ctrl+dragging it along the curve? it seems to copy it along the spline. that saves you time from rehosting.

  4. This stuff is way above my head, and my Revit skill, but fascinating to see, nonetheless. Thanks for sharing your exploration!


  5. Hi Adriel,

    Thanks for the tip. Sounds like a good one, will try it tonight. More tasty treats to come by the way :-)

  6. i see that you are having a fruit bazaar now! Your research is really compelling! Btw how did you give the avocado skin a seperate material from its cross section?

  7. Hi Adriel
    Paint ... there was a time you could paint with a material parameter inside family editor, but that seems to have gone away. Can still paint with a fixed material though, that way different surfaces of the same solid can have different materials.


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