Thursday, October 27, 2011


Post 5 for the Pumpkin Competition.  Need to start carving.

To hollow out the middle we could use a revolve.  Conceptual massing doesn't have a separate revolve tool, just draw an axis line and a closed loop like you would with the normal revolve tool, and "make void form".

So how about the eyes ?  Make a triangular profile that is resizeable in a separate mass family.  Load into project. Draw lines radiating out from the centre of the pumpkin, add angle parameters. Host a point on those lines, make reference plane visible, place triangle on plane.  Selec line & triangle, make void, Revit knows it's a sweep.

Let's pause here.  Is anyone else getting worried ?  It's all getting too messy.  How am I going to link all this together so it resizes as a unit ?  What does it equate to in the real world ?  Let's back up a bit and try something a bit simpler. 

Imagine we want a hollow Doric column (precast or GRP maybe)  All we need is another set of profiles, scaled down by a factor and used to define a void. Probably we want a smooth circular void. We already have a circle profile in this family, so it's easy to create another 3 types and link their radii to the outer profiles.  This is nice, because we only have one more parameter for the end user to worry about.  I called this "Void factor" and set it to 0.8    Inner Radius = Outer Radius x Void Factor

The result is still quite robust and versatile.   I spent a little time on the dialogue box organisation & parameter naming. I've made an effort to arrange things logically and think about ease-of-use, but probably it could be distilled down further.

Need to be careful with the convex "pumpkin" versions because the shell can get too thin and the family breaks.  Maybe we could find a way of linking the bulge factor & void factor together to avoid this.  Clearly the re-entrant forms are going to be difficult, but there is potential here.

There's been a dynamic going between organic & geometric, make-it-look-like-a-pumpkin v do something useful & interesting, one off originality v the common good.  And if I really wanted to make a pumpkin that is convincingly real, re-sizeable, with optional carved voids, I'm probably more than half-way there. 

But the offshoots and by-products are too rich to ignore.  So I let myself get carried away for a while. . There is a treasure-trove of semi-automated form finding on my doorstep now,  with copious references to flowers, jellyfish, starfish, lemon-squeezers ...    I'm also well on the way to a whole battery of classical column families.

Perhaps this whole exercise with its flip-flopping between pumpkins & columns is an apt metaphor for architecting in general.  Oscillating back and forth between what we would like & what we can afford

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