WEEKEND ON FIRE

I am not religious. I look for spirituality in visual and musical explorations.

Musically I was drawn to the blues, improvisation around simple themes, finding complexity in happy accidents and the mood of the moment. My visual side has been entwined with the practicalities of building for so long that it’s difficult to disentangle the bricklayer from the artist.

Sacred buildings loom very large in the histories of architecture and building technology. In this blog I have explored the churches of Hawksmoor and Soane: Borromini and Corb.  Formally and culturally there is great diversity in these examples. The world of Gothic Cathedrals is something else entirely.

One recent, happy accident was my decision to model Winchester Cathedral under extreme time pressure. That experience collided with current events and online conversations to goad me into attempting a similar exercise on Notre Dame. There are ambitious ideas floating around, but for the moment my focus is on a personal learning experience and the opportunity to share that via the Internet.

For the Winchester model, I created a generic pointed arch controlled by 3 main parameters. (width, height and pointiness) I am able to create new types on the fly as I blunder my way to a deeper understanding, extrapolating from a few reference images.

These days it’s not hard to find a floor plan, a partial section and a couple of dozen photographs covering the main features of any well known building, inside and out.

There will probably be a scale bar that you can crosscheck against a screen grab from Google Earth. With luck you can turn on the 3d button and orbit around a crude textured mesh.

I always start with grids and levels. This implies simplifying, ignoring minor irregularities. I’m fine with that. My purpose is to understand the underlying logic, to burn the fundamental structure of a building into my brain. To know it “like the back of my hand”  (or Highway 51)

I used to spend several hours, obsessing over conflicting information. These days I prefer to make quick decisions and get on with the job. Get stuck in. Learn by doing.

Notre Dame starts off as a nave with double aisles down each side. Then you add a row of hefty buttresses to resist the thrust of the vaults above. Eventually the spaces between these buttresses become roofed over and incorporated in to the main space, almost like a third aisle.

It’s very interesting to link in the Winchester model and compare. When I was there it felt like such a soaring, lofty space. But compared to Notre Dame it seems to lie prostrate on the ground. Is there a cultural difference here? Pragmatists and Purists perhaps? English compromise v French passion? 

The flying buttresses at Winchester are rather tame compared to those of Notre Dame.  (a bit like comparing a grouse to an eagle perhaps)  But the same strategy works well enough, at least for these early stages of exploration .  Set up a section view with a reference image placed and scaled.  Apply some transparency to the view so you can see the image behind the walls.  “Edit profile” and trace away to capture those soaring arches.

At some point, that generic arch needs to be differentiated into a series of more specialised families. The first of these is an archway perching on round columns. Usually each arch needs just one column, but sometimes at the end of the row you might need two, and at right angles, a type with no columns to connect between two rows. 

The floor plan from Bannister Fletcher seems to show a small half-round chapel at the apex of the apse, but Street View suggests otherwise.  Every time I attempt a model like this from a jumble of source material, I come across conflicting information.  Is this a mistake?  Was there a change at some point in time?  Interesting questions, but for now we will go with Street View and plow onwards.

The triple ambulatory at the east end is quite tricky. I came to a solution for widths and angles, based on trial and error. It will be interesting to analyse this more carefully some time and to make customised families with splayed reveals perhaps.  The vaulting here will also present a fascinating challenge.  Seems to be a “concertina” in plan, with three arches along the outer curve and two on the inner,

I made the the “all purpose” arch family using the “Door” category.  As I proceed to diversify these, some must become windows.  “Save as” with a new name, delete the types you don’t need.  Load back into the project.  Swap out the types you are replacing with this new family.  Go back to Family Editor and change to a window.  Load it in again and overwrite.  Those instances have now become windows.  I created a nested “Infill” component for the windows.  Ultimately most of them will become a detailed family with only one type and very limited parametric behaviour.  No point in trying to make all that Gothic tracery parametric.  For the moment it’s just a sheet of coloured glass.

Essentially, the original parametric family is a learning tool.  My model evolves along with my understanding of the building (its 3d form, the underlying relationships, functional factors driving these, historical context, etc.)  Perhaps we could think of the arch family as “scaffolding” or the temporary formwork that allows you to build a stone vaulted ceiling.  It serves its purpose in the grand scheme of things and is put aside for the next project.

So the model is shaping up, and I’m discovering all kinds of interesting features.  There are spiral stairs in at least 4 places, hiding inside buttress-like forms that project out from the exterior walls.  And the roof around the ambulatory seems to be much flatter than the normal aisle roof.  Is there are step at the meeting point of these two slopes? Difficult to be sure from Google Earth 3d.

Maybe I will find answers by inspecting the mesh model inside Assassins Creed.  I don’t normally play games, but this one has been made available as a free download for a week, so I decided to take a look.  40gb wow! 

One day left. Need to have a go at the vaults. I remembered the term Sexpartite from my schooldays, and looked that up online.  Some useful images, but nobody explains in any detail how to set out the geometry.

Well, that will have to wait for another weekend.  I ran out of time and only managed a basic gothic cross-vault.  At least this allowed me to set up a camera angle that makes the model look more complete than it really is.  Instant render from Enscape3d, process the image in PIXLR and that’s a wrap for a very intense weekend of learning by doing.