Sunday, October 21, 2012


I'm aiming at an aubergine, you lot call them eggplants :-)  Start with a closed profile, it's a modified version of the good old faithful Doric.  This time all one side gets the large radius and the smaller radii are grouped together on the left.  Because this is based on the profile I used for the sweet potatoes, there are other subtle irregularities, eg spacing of the points.

This profile is applied to one of my "scaleable curve" rigs.  As before this is just a rectangle divided up using hosted points and splines so that all the relationships remain proportional when you change length and/or width.  Space profiles of different sizes along the curved spline and "create form"  With a bit of tweaking you can make a passable eggplant.

By chance I selected one of the profiles and pressed space bar.  Interesting result.  The irregularities lead to some serious distortion.  It's helpful to view this in elevation.  Because the profile is made from two splines there are 2 seams running down the full length of the eggplant.  Seen in elevation these appear quite complex, almost irrational.  Rotating one profile immediately creates a much wilder ride for the 2 paths, and transforms the eggplant into something more like a joystick handle.

Just as an aside, the elevation view illustrates one of the differences of using a BIM programme to to this kind of stuff.  I'm sure it would be far easier to model vegetables realistically in Max or Maya.  That's why movie animation is done in those kinds of programme.  Apart from the fact that I am not fluent in either of these programmes, Revit has certain advantages in terms of helping me to think about what I am doing and why.  (otherwise known as philosophical reflection or perhaps critical thinking)  It comes down to the way that BIM combines 3d modelling with orthographic projection.  This is at the very heart of the initial BIM concept and it facilitates "practical designer thinking". 

There is a danger of thinking that 3d is everything, but actually in historical terms, orthographic projection was the big breakthrough.  Artists had long been constructing perspectives when engineers formalised the conventions of 1st & 3rd angle projections.  And although BIM as a software genre only emerged during the second half of my lifetime, the reality is that practical designers have been combining realistic 3d with abstracted 2d for many generations.  There is a very nice drawing by Nicholas Hawksmoor that I often use to illustrate this.   It is a hand drawn version of the single building model we get so excited about, and it's roughly 300 years old.

But back to the eggplant/joystick.  I've stumbled across something here.  This combination of curved path and lumpy profile of varying size seems to have secret powers.  Successive space bar rotations of different profiles produce an unexpected variety of forms. 

Many little idiosyncracies of family editor interface.  Properties shows family category & parameters when nothing is selected (not view properties)  On the positive side that makes these settings more accessible.  But it also makes view properties harder to discover.  You might even assume that you can only access them via the ribbon.  Personally I think I would rather have the 'famly types' dialogue available in modeless form as the default.  I certainly use this more often than "categories & parameters".  Flexing would be much easier.  And while I'm in grumbling mode, I don't quite understand why the steering wheel doesn't remember that I prefer the full wheel but keeps defaulting to the basic wheel which doesnt have pan and look.

But I should also mention the great new stuff.  The transparency slider is great for this kind of work, also the gradient background in elevation views.  It really helps me to have this kind of stuff in family editor so I can see the forms I'm creating more clearly.

Before I forget, the bulge factor still works on the profile.  Some odd results when pushed to extremes.  Get something that looks like the rubber bone we bought for our dog, and maybe one of those lumps of rock you see floating past in space movies. 

Store that thought away, it may come in useful one day.  Perhaps I'll come back and make some lumpy potatoes by tweaking this.

Now for a diversion.  I want to explore leaf-making techniques.  First thought is to connect together a series of splines, form a surface, push and pull ... lots of different leaf shapes.  Didn't work out.


Revit is a bit choosy about whether or not a set of splines can be used to make a surface.  It accepted 4, but didn't like 3 of the same 4.  After a while I started to feel I was drifting off into no-mans land.  Need to keep my eye on the ball. 

But where is the ball ?  What is the brief ?  The way I interpret it, we have considerable freedom to define our own brief, but that's not the same as saying "anything goes".  Actually you have to think a lot harder when you are setting your own brief.  And this is where, once again, despite it's "silliness" the pumpkin game connects to real life issues.  Architects are notorious for ignoring the client's brief and pursuing their own agenda.  That's fine, but you have to keep asking yourself "how do I justify this" & "am I being self-indulgent, or does this idea have real potential"

My brief here is to explore the boundaries of what I can make with Revit's conceptual massing tools.  I'm looking for techniques that are robust and fertile.  Just making wierd shapes for the sake of it doesn't count.  Super-realistic renders are nice, but they are not the goal, just part of the working method.  Same as in real life.  Knock-out images can sell the project to the client, but you still have to build it, so keep that at the back of your mind. 
So I went back to my rectangular rig idea.  That's a winner.  Can I use it to make leafy stuff ?

I made a new profile.  4 points, 2 splines, couldn't get much simpler.  Then I made a rig that was sort of like a fractal branching thing.  Hosted some points and joined up a set of curvy splines.

Yet again ... one of the little techniques that this year's pumpkin competition helped me to discover.  Hosting points, making them visible, setting the workplanes one-by-one ,,, it get's tedious.  Do it once, copy a bunch of point/profile pairs onto the floor.  Select and rehost, select and rehost ... much faster.  (STOP PRESS just got a hint from Adriel that "ctrl-drag" will copy a point/profile combo along the line, which is even faster, thanks for that !)

So I created something quite nice.  A bit flat, but rotating some of the profiles helped.  There is potential there, but what I really want is a stalk for my eggplant, with those nice pointy leaves left over from the flower stage.  So eye back on the ball, and I think maybe what I need is one of my tomato stalks with a void that cuts away the valleys.

Actually I went back to the sweet potato and adjusted the profile sizes.  Takes a bit of patience, because sometimes the error messages don't mean you have reached the limit.  Often you find you can push beyond that limit, but there is a small range of values that don't work.

I tried making a void using the same profiles, just rotated so that the high points match the lows, and hosting them on the same backbone. It began to work, but I couldn't get the deep cut I was looking for. 

So I went back and made a much simpler 5 point profile.  Three different sizes hosted on the backbone to make a pyramid-like void.  I'm happy.  It's not quite like a real-life aubergine, but it looks leafy and it fits

I didn't finish linking the void profile sizes up to the scaling parameters yet, so I am stuck with a giant eggplant to render.  All part of the fun. 



  1. Interesting. My Corinthian leaves all use just three profiles. However, I had to tweak quite a lot to get ones that didn't error out... Hmmm

  2. Hi Paul. Yes you can definitely get 3 profiles to work sometimes, but not those 3. I wish I understood the "why" of this but often I am reduced to trial & error. Hey ho.


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