Sunday, November 10, 2019


 Picking up from the previous Notre Dame post.

During the week I had assisted one of our architects with a tricky stair detail. The only way I could get the curved glass balustrade to reflect the design intent moderately well was to create multiple in-place swept blends. A bit of a hack, like the photoshop-compiled image shown here, but I quite enjoyed doing it. 

It brought back memories of the spiral stair family that I developed in 2012, and I decided to try using this for the spiral stone stairs that occur in several places at Notre Dame. I guess these are the equivalent of the modern service lift. 

The upgrade from 2012 to 2020 went smoothly enough, but it is a bit sluggish to respond to changes in parameters. Not all that surprising given that the treads are generic models nested into curtain panels on a divided spiral surface. 

At the sides of the Bell Towers, I think I have the levels of the landings more or less right now. Had to drop the upper vault down so that you can squeeze a door in under the little sloping roofs.

But the 4 stairs at the outer corners of the Transepts are much more challenging in figure out. There are doors leading off in different directions at various intermediate levels, and they don’t all connect to the triforium gallery. I had to make do with a placeholder spiral from top to bottom and a few indicative doors. 

A screenshot from the Revizto model we exported for BiLT EU. 

I’ve been watching videos on YouTube about different French cathedrals. At some point it brought back the idea of doing comparative studies of different apse geometries. Clearly many different solutions have been tried.  Here are 4 variations on apse geometry. Different numbers of half-round chapels clustered around the curve, two cases where the central one is different.

I created two more visuals from my wooden block model. One breaks down the inner core, so it comes before the other six I created, building up the aisles, buttresses and chapels around this core.

The lower portion is an RCP view, showing the distribution of 4, 6 & 8 part vaults. (Red C means Chapel.)  Around the edges, photos of various vault types.   The more I study ribbed vault technology, the more impressed I am.  800 years ago takes us about halfway back to the fall of Rome.  Was that collapse the “reset button” that paved the way for modernity?  Medieval Europe, emerging nation states, the “freedoms” of city life, the stirrings of technological innovation?

Ribbed vaults are vey different from the plain vaults that preceded them. They allow complex and highly varied geometries to be built, but at any stage in the process you only need to support one row of voussoirs with a wooden form shaped to a simple radius.  You can start with a four part groin vault, then subdivide one side into two vaults, or choose any of the outer arches and raise it higher or drop it lower.  It’s a very impressive technology: structurally, aesthetically, methodologically.

It’s interesting to compare the current model with the one I produced in that first weekend 7 months ago. Certainly, we have come a long way in that time. And what a journey, each team member finding a different area that catches their interest and pursuing it with passion. 

The other cathedral in that image is, of course, Winchester. The one-day massing study that kicked this whole thing off. 

I have been telling myself since I got back from UK that it would be useful to do a comparison of the 4 cathedral towns that I visited: Winchester, Salisbury, York and Chichester. So far, I have managed one town map, drawn with the stylus of my Samsung Note 8, using Autodesk SketchBook Pro, and tweaked a bit using PIXLR. 


Classic Roman town layout, rotated slightly to be parallel to the river. North/South axis is displaced from the centre by the cathedral, which occupies most of one quadrant, as cathedrals often do.  The main street is East/West, perhaps reflecting the fact that London is to the East and Salisbury to the West (roughly speaking)

We have two grotesques in the model now, thanks to Ryan. The "Edge-Hiding" trick is doing good service (using MAX), and of course, the CAD mesh needs to be “bylayer” so as to pick up the material assignment under object styles (Imports in Families)  CAD layers become subcategories which can be renamed within family editor.  I'm using the subcategory "Statue" for this purpose, the same one used for the row of kings, lower down on the West Front.

I  adjusted heights based on the TruView coordinates tool. You have to adjust the zero which is derived from the scanner position at the first survey point, tripod height above the triforium gallery. Generally everything was stretched up a bit vertically. Maybe it would be better if we were just slavishly following a point cloud. Or maybe it’s good to be forced to look carefully and to practice judging proportions by eye. 

I generally take the role of impetuous pioneer, rushing ahead and clearing the undergrowth. After dropping the clerestory windows I had to adjust roof slopes in the dropped section along the nave.  Lots of little adjustments actually, and zipping around the model with my new VR setup.

The zig-zag vaults on the upper level were missing and I had been thinking about my pumpkin adventures. I decided to revive my box rig and have a go. This is Alfredos territory really, but he’s  not going to get around to it until after AU. Maybe it will be interesting to approach things from a slightly different angle. 

The box provides a framework for reference lines and points which define geometry. Vary the XYZ of the box and everything adjusts accordingly. So this is my version of a triangular vault, made from three surfaces. Each surface is lofted from 3 arcs. That’s my interpretation. 

There are offsets to vary the skew. Mid triangles in a group of 3 are symmetrical. The two sides are skewed. 

The sexapartite vaults were pretty crap at the sides.  These are skewed triangles, but just two surfaces. So I developed a box rig for these also and exported SAT surfaces to nest into the family, replacing the ones I had before.

The vault next to the organ has unequal side arches. It’s as if one is squashed to make way for the heavy ribbed columns that flank the organ loft.

Jumping around now trying to fix the more obvious shortcomings of the model.  The steps leading up from the triforium galleries to the bell ringing chambers start out as wood, but the last few risers are in stone, formed within the thickness of the wall. So I roughed these out.  Then I switched to the choir area and fleshed this out some.  I had forgotten who made the altar.  Turns out it was John Wehmer, back in August.  Thanks John, finally brought it into the main model.

Behind the high altar is a pieta.  I placed a plinth and a crucifix, we can add some statuary later.  There are statues of kings at the sides.  I used cut-down versions of one of the figures from the west front.  Somebody could adopt this area and develop it further.  I’ve just done the minimum to give some ambience.  Not happy with the floor materials though.  There are raised floors in the whole of the east end with extra height around the altars.  I hadn’t really taken note of this before.  I made a start on representing these changes in level.  I have to say the space still looks a bit empty.  The railings are far too plain at present, and the gates are not indicated, either in plan or 3d

The sheet set is a bit spruced up now.  I cleaned up my sheets and added a few annotations.  Alfredo added three splendid sheets to the set. 

I think that's it for today.  I wish I understood the middle ages better.  So many fascinating questions.

Tuesday, October 29, 2019


This is the second in a series of posts looking back over nine years of blogging.

An awards dinner, an honourable mention and I seem to remember getting rather drunk with on of the partners. Our submission for the BIM category was rather too complex and unconventional to be an outright winner. But the project was a tremendous learning experience for me, which is surely the greatest prize. Topography is another of those love-hate features in Revit.  One day we will have a better solution, but you can actually do an awful lot with Revit topo, as I found on this project, it just takes time.

I had a young Australian friend in the office around this time.  He was a design architect who was the value of starting early with Revit.  Sadly he was a bit out of step with senior management and eventually he moved on.  But for a while we had some great discussions and I tackled all kinds of challenges that he presented to me.  In this post I showcased some renderings that he did in his spare time for a private client, all from Revit, some with the inbuilt render engine, others using the link to Max.

I picked up some tricks for processing Revit output in Photoshop quite early on via the internet, and over the years have tweaked and varied these processes in different ways.  This post covers several useful techniques using real life examples from my day job.  The most fundamental trick is to export a hidden line view and a render to the same width ( in pixels) and put them on different layers.  Then you can use various blending and masking techniques to make the image resemble a hand-drawn perspective.  This is another example of giving our minds just the right cues to jump to a useful conclusion.  We are always favourably impressed with a well-drawn sketch from real life.  It gives us a warm and fuzzy feeling, connects to works of art in the labyrinth of connected neurons within the cerebral cortex.  Most of this is subconscious and all the more effective as a result. 

If you can manipulate an image from the model in 5-10 minutes then it is really worth doing.  If it takes much longer than that, then the pain of having to do it again when the model changes becomes too much to bear.  That’s my rule of thumb.

Archicad.  I played around with early versions before Revit even existed, and could easily have ended up a devoted user.  But life took a different turn and I ended up in a Revit office.  There was a seminar about this time that advertised itself as a BIM event.  In the end it was exclusively about Archicad, although this wasn’t made at all clear in the blurb.  No big deal, it was quite interesting, and I find the animosity thing between fan bases very boring.  There are pros and cons.  I have heard different opinions from believable sources.  In the end I think it’s about what you can do with the software, most of all what IDEAS you have to share (design ideas, historical ideas, interpretations)  Michelangelo was not defined by the quality of his chisels or his paint brushes. His technical skill was important, but much less significant that his vision.  Can you express yourself with BIM?  Do you have something to say?

Another interaction with a supplier at a CPD session.  Stamped concrete is an interesting technology for quickly and cheaply mimicking natural materials with complex textures and variability.  I tried to convey to this company rep how useful it would be if they learnt how to set up Revit materials for their wide range of finish options.  She showed some interest but didn’t really pick up on it like I had hoped.  One day.

This post is centred around my decision to share a bunch of furniture families.  I’m a firm believer in open sharing of content.  I had been to Uganda a little while before and wanted to use the post to express some broader thoughts about fair trade and the enormous variations in lifestyle and living standards between different global regions.  I don’t believe in simplistic solutions or in blame culture/virtue signaling.  I think we need to be honest and aware of reality.  Do our best to interact positively with the world around us.  Cherish the good things in the societies we inhabit.  I feel privileged to have lived on three continents for over a decade each.  Been a hell of a ride :)

Ceilings.  Another bug-bear.  How do you do coffers?  There is a hack that allows you to smuggle system categories into family editor, but it’s a bit suspect.  Would be nice if it loadable families could be assigned to a ceilings category.  Anyway this is a family I developed around that time.  Ceiling-hosted, cuts a hold and inserts a coffer, type in the width, length and height, specify the lighting cornice moulding profile.  Haven’t used it in a while.  Front of house has been handled by a separate sub-consultant on most of my recent jobs.

And here comes the pumpkin experience.  This was another of those remarkable coincidences that keep cropping up in my life. I received a suggestion from a follower for a scalable profile for the doric columns in my “lunch with the gods” post. It was tour-de-force with formulae galore and using point world.  A light bulb moment occurred, and I came up with my own solution, which just so happened to allow for the profile to turn itself “inside out”.  A second light bulb popped up and told me that an inside out Doric Column was in fact a pumpkin.  All this as Zach Kron was announcing his annual competition.  A bit of fun which had produced some fascinating entries over the past 3 years.

Light bulb number 3 said to me “why don’t you do your competition entry as a series of live blog posts?” … a feat of reckless bravado that served as an incredible motivator for me as I ramped up the complexity of my submissions for 4 competitions in a row.

Now my “way we build” hat said “this is a perfect opportunity to model Adolf Loos entry for the Chicago Tribune competition, which took the form of a giant doric column.  So that was the basis of my second post.  Amazingly I have never gone back to develop this further.  But it was a good exercise, using wall-by-face to convert a massing object into a real building.  Along the way, I had already discovered what an astounding array of forms my parametric family was capable of producing if I added a parameter to swap out different profiles.  This on top of using the same family for the whole building and the three storey columns framing the entrance.

Post 3 accepted the challenge of making the pumpkin version more organic.  Allow a couple of the lobes to have a greater “bulge factor” and apply a textured material.  Not bad.  Render it up, add a bit of cinderella stuff in the background.  Quite a story line developing here.  Why did I add the 4 points of Le Corbusier?

Now once you have an organic thing going, there are all kinds of possibilities.  It could be more of a gourd than a pumpkin or it could even be a mushroom.  Suddenly we have switched from Cinderella to Alice in Wonderland.  I was getting very interested in blurring the boundaries between BIM and fantasy, BIM and art.  Pushing back against the “nerd” label I suppose.

I explored methods for making the pumpking hollow, and this led to even more metamorphoses.  You could turn it into a 1970s lamp shade, or some kind of jellyfish, maybe even a lemon squeezer.  Self-intersecting geometry even seemed possible without breaking the family.

My final post was a set of conclusions and reflections.  What had I achieved?  What were the limitations?  How could it be made more user friendly.  What were some of the potential applications of the ideas that I had explored?  Then I cleaned up the different versions of the family, popped them into a project in an orderly manner and … submitted.

As an aside, this was an early example of my attempts to bring freehand sketching back into my work process.  I think I drew these on paper and then coloured them up in photoshop, but I did by a funny little device called an inkling around that time also.

It was an incredible year for submissions.  Marcello also tackled metamorphosis, but in a way that was more “Hammer Horror” than “Walt Disney”  Phillip Chan designed a pumpkin-based apartment block.  So I was thrilled to stand on the (virtual) podium alongside these two giants who have since become good friends.

That’s chapter 2 of my "blog story" folks and I'm feeling quite nostalgic.  A year on from my very first post and a head bursting with ideas and motivation.  Where to next?

Monday, October 21, 2019


First off a shot of our Revit model of Notre Dame, as a VR experience at BiLT EU (Edinburgh)  Sadly none of us could be there, but it was good to send our baby along instead.  Thanks to Cameron for the pic.

I’m preparing for my AU session. I wanted a better image for the slide about maintenance access routes. So I decided to insert a representation of the spiral stairs. If you look carefully, the stairs don’t arrive at the right place for the doors. Actually some of those doors are in the wrong place, anyway. We are still figuring it out. Which means, model something. Take a look at it. Ask interesting questions. Come back a few weeks later and have another go. Rough sketching with BIM.

Q) When is an elephant not an elephant?  

A) when it’s a grotesque.

This weekend I added the first grotesque to the BIM360 model, essentially a collaboration between Ryan and Francois. Actually I added it a couple of times. When we have more variations on the grotesque theme I will dot them around all the internal and external corners of the skywalk.

Ryan also contributed a detailed organ model to replace the very basic placeholder I knocked together early on. So I loaded this up and fleshed out the flanking walls a bit, correcting alignments, adding arched recesses and little bundles of colonnettes. Great work Ryan, by the way.

I also placed a vault at the top level. It’s the same hexapartite as used on the nave and unfortunately doesn’t respond to parametric controls, but will have to do for now. I’m very conscious of how much remains to be resolved, but right now I can only touch issues lightly, here and there.