Monday, August 31, 2020


For a couple of years now I’ve been telling myself I need to do shorter posts and get them out twice a week.  More immediacy.  I get a bit frustrated by how long it takes to do some serious modelling, assemble the pictures, write the text, review & post ….

Problem is that long thoughtful posts are my trademark and I really enjoy having ten years worth of carefully documented explorations to look back upon.  Then last weekend I stumbled across a solution by accident. While working, share a single image and a couple of sentences directly to LinkedIn.  I think of it as my version of “Live Streaming”.  Give people a sense of what’s happening in real time when I start using my BIM pencil to look more carefully at one of the hundreds of buildings that have caught my attention over the years.

St Mary’s Limehouse by Nicholas Hawksmoor 1713.  I lived almost next door to this church for a few weeks some 40 years ago, and I did an “urban design study” of all six of Hawksmoor’s London churches … when was that?  2014 apparently.  So that must have been inspired by visiting my son who had recently moved into the area.

7000 views is not going to make me a celebrity, but it’s wonderful thing to have these global interactions.  More conversations over the past few days than I normally have.  I don’t want to get swamped by people wanting to chat on line, but the interactive nature of this process is absolutely crucial.  BIM is inherently collaborative.  That’s one of the reasons that it’s such a powerful research tool.  Far too much “art history” is dry, academic, text-focused stuff.  I really think that a bottom-up action-research programme could shake up the field and democratize our heritage. 

That’s what the “BIM pencil” and “the Way We Build” are all about.  We live in the age of slogans, and those are my two big contributions to the genre.

For me, BIM is an outgrowth of “drawing”, an activity with a very deep history which engages our subconscious brain and our physical bodies. That’s part of what the “BIM pencil” metaphor evokes, and it’s important to me that I include the activity of hand-sketching in my workflow.  You might say “that’s not BIM” but I might respond, “that’s a very narrow-minded view”.  At the moment I am mostly doing the hand sketching “in parallel” with my BIM work, but there is a back and forth, AND … I am super keen to see hand-sketching better integrated into the core of BIM.

At the end of the first weekend, I produced a sheet set, which I really want to do more often.  That was my first time to drop it directly into LinkedIn.  Seems like a great way to share my work in the spirit of “lean & agile”.

This work on St Anne’s is only happening because I visited London a year ago and trekked around all six Hawksmoor churches, ending up with a tour of St Anne’s, graciously offered to me, via LinkedIn by Rufus Frampton.  He is one of several people from a building trades background with passion for built heritage who I had met online and who agreed to meet up during my visit.  Those friendships have continued to blossom, and become extremely important to me.  We cannot allow BIM to become trapped in a nerdy tech bubble.  It must belong to the entire range of activities that contribute to making buildings, from Stone Masons to Ironmongery manufacturers, to Surveyors.


I was struck, during that visit, by the richness and variety of Stone Carving on display in the centre of London.  Beautiful creative studies that build upon ancient traditions, and offered building workers an opportunity for artistic expression.  I include one piece in the Art Deco style, even though it is rather stiff and flat compared to the others, because it seems like that was the last vestiges of original stone carving applied to new buildings.  We still have stone carvers, I met some on that visit, but their commissions are coming from the “heritage” industry, or the “art objects” industry.  That’s my impression, at least.

It makes me sad, but I don’t think there are any easy answers.  Industrialization is a wonderful thing.  It has dragged billions of people out of poverty.  BIM and off-site manufacture are going to play a crucial role in dragging the last 20% out of their poverty traps.


We also need to attend to quality of life. Obesity is a product of affluence.  Sitting down at a laptop all day as I often do, is not a great future for humanity. At some point we need to engage more humans in creative, manual work.  Ideally we should all balance our activities out with something like stone carving.  That’s why I have been trying to do some physical, sculptural work during this Covid hiatus … in a very small way.

I went “up north” where I grew up and stayed with my cousin for a few days.  While there, I met up with a couple of master plasterers.  The great thing about social media is that once you have a couple of connections in a particular sphere, you start to see activity by others.  Over the past year I have learnt a lot about the techniques used in the plastering trade.  I have been fascinated since 2014 with the Corinthian capitals on the inside of St George, Bloomsbury. They are wonderfully delicate and sculptural.

I was pretty sure this was plaster work, but were the leaves separately cast and assembled?  I wasn’t sure, but by now I’m quite confident.  The approach is modular.  The materials used in plastering are almost unique in allowing solid castings to be stuck to a backing using essentially the same stuff. 


The entablature above those internal columns, contains enrichments (assembled in a similar modular way) that echo the ones I sketched on my phone a week ago, found on the outside of St Anne’s Limehouse, carved in stone … a very different kind of process.  There is one row of Egg & Dart plus three variations on Leaf & Dart ( I guess). 

I have explore ways of representing these kids of elements with my BIM pencil.  There are computational load issues for sure.  We surely need ways to digitally connect low res and high res versions of details like this so that they can be seen withing the context of the model without blowing up our laptops, and  detailed out for close-up shots and for passing on to specialist trades.  I have yet to see a robust proposal for those kinds of phase shifts. 

How can BIM workflows connect together the data between joinery details, complete building models, urban planning studies, whole city models.  Could we do bi-directional updates between these different scales in the same way that we do within a Revit model (for example) ?

I started with an Enscape-derived image, and I will finish with another.  The site context is linked in from that urban context study that I did in 2014, so that stuff in the background is St George in the East with Christchurch Spitalfields beyond.  They are much closer here that in real life, but it creates quite an effective image, giving the impression of the East End of London 300 years ago … basically a string of villages along the Commercial Road with a mixture of market gardens and shipping related activity like rope making sloping down to the river. The docks came much later, in the 19th century as the Industrial Revolution came into full flow.  Up to that time the river itself was able to handle all the shipping, with wharves and warehouses up against the edge. 


Sunday, August 23, 2020


I have been trying to merge the digital and the manual for many years.  Specifically, I began to buy digital sketching devices around 2012.  I had used a Wacom tablet a couple of times but looking at the screen while moving your hand in another universe did not replicate the natural fluency of drawing for me.  And so, in 2012 I bought the “Inkling”, a strange hybrid device which allowed you to sketch on paper with a rather fat ballpoint pen, while a sensor, clipped to the edge of the paper, converted those movements into bitmap files.

The fluency was wonderful.  It was easy to capture my natural drawing style.  But size was very limited by the range of the sensor.  There was no way to go back and add to something you were doing yesterday, and the whole business of setting it up and downloading the files was quite cumbersome.  The initial promise faded and it fell into disuse. I did use the sketches in a couple of blog posts and was rather proud of the extra punch I could get with a couple of minutes adding colour in Photoshop.

I should really try to emulate that style with my current technology.

In 2013 I bought a Microsoft Surface, the very first model to come out.  For a while I had a full set of Windows devices (Phone, Tablet, Laptop) which seemed like the obvious way forward to me, but it didn’t catch on with the mass market, so the phone eventually fell by the wayside.

The stylus available for tablets at that time had a thick spongy ball at the end.  Slightly better than drawing with your finger tip, but not really comparable to the fluency of the Inkling.  Drawing directly on a decent sized screen was good, and I became aware of the Wacom series that has a built in screen, but wasn’t yet ready to splash out on such a device which would be too much to carry around on a daily basis anyway.

My collection of Surface sketches is not very impressive, but you can see that I am trying to find a digital replacement for scribbling on random bits of paper.

There is a gap of about 3 years.  Then I was persuaded to buy an iPad pro with the Apple pencil.  I was disappointed with the pencil and I decided to splash out on a Wacom Cintiq by way of comparison.  The iPad is always at hand but the stylus feels like plastic on glass, too slippy by far.  The Wacom has a great feel but you can’t carry it around with you and the cables are a bit of a pain.  Nevertheless I did some interesting work with these two devices.

Finally I felt like digital drawing could compete with the manual version that had been one of my primary thinking tools for more than 60 years.  Quite a bit of “traceover” work here, but also a couple of pics where I just started drawing on a blank sheet and made it up as I went along, tapping into the awesome power of our subconscious brain.

All the same, digital sketching had not become a daily activity in the same way as pencil and paper.  That was only to happen in 2018 when I finally gave up on my Windows phone and bought a Samsung Note 8.  The screen may be small compared to the iPad, but the stylus feels better.  It seems to grip the glass very slightly which is much closer to how a pen or pencil feels on paper.  Also the charging arrangement is about 10 million times better.  You don’t even have to think about it.  Finally the phone slips into your pocket.  It’s the one device you are going to have to hand almost wherever you go, so you can do a quick sketch whenever the mood takes you.

Once the Samsung phone had made digital sketching a part of my daily routine, the iPad could gradually creep back into play.  This happened after my trip to Volterra in Tuscany for a reality capture workshop.  Back home I felt the need to look more carefully at the images I had amassed.  There is no better way of looking perceptively than the process of drawing.  As a species we have been doing that for at least 30 thousand years: representing objects from life by drawing on to surfaces and transforming out grasp of reality in the process. From the caves of Altamira to Picasso’s rapid sketches on glass we have been thinking aloud with the “hand-eye-brain” loop that is embodied in the act of drawing.

There is an interesting range of expression here, degrees of abstraction, flat colour v grainy texture, muted tones and garish colour.  The value for me was in the process, the hours spent developing fluency with digital drawing tools.  Doing the work.

In early 2019 a visit to my good friends in Hastings, Nick & Jane, prompted attempts to work more rapidly, to use a freer line, adopt a more impressionistic mindset.  It takes effort, and it’s not always the correct approach to a situation, but it’s really, really important in terms of merging the digital and manual worlds of visual thinking.

HAND-EYE-BRAIN-DEVICE.  We have all become cyborgs to some extent.  Not sure it’s as dramatic as that sounds.  There is a very deep history of transforming our reality with devices.  The way that fire impacted our digestive system and jaws (perhaps a million years ago) was arguably more dramatic than the “digital revolution” we are now experiencing.  Difficult to compare though.

Stone tools, Language, Sedentary life, Houses & cities, specialized trades.  Culture takes the form of physical devices, of institutions, habits of daily life.  Many animals have culture to a certain extent. But we have made it the hallmark of our species. 

Which brings us to the year of Covid.  A couple of pre-covid sketches take very simple images and try to explore the very personal meaning behind them.  My hand resting against the window of a train as we rumble through the English countryside.  The simple barred window of traditional gulf architecture set in a rough textured wall, stained with the ever present fine sand that gets into everything.

Then a series of freehand inventions, trying to capture the flowing scrolls and foliage of the classical idiom.  I want to go beyond tracing over carefully chosen examples.  Just start drawing.  Invent on the fly.  Try to internalize the unspoken rules, expand your natural vocabulary.  The fourth in the series is a venture into the third dimension with plasticine on a textured tile background.  I’m still intending to make a latex mould from this and cast it in plaster.  Extend the range from digital sketching, via hand drawing through to physical object. 

BIM is my “main thing” but let’s continue to blur the boundaries.  If BIM is to fulfill its promise, it must overlap into the world of stonemasons, carpenters and plasterers.  We can’t just live in our heads and our “social media presences”.  That’s the brain freeze of lock down.  Make the connections, not just to a set of group think “friends”. But to the world of work (and play) out there on building sites and city streets.

A couple of months ago, at the height of lockdown I attempted to breathe new life into work I did in the 1980s in Zimbabwe, my adopted country where all three of my children grew to adulthood before we all found ourselves merging into the economic refugee community (legal immigrants all, I hasten to add … I have every sympathy for the youth of Africa, but I don’t believe we are helping them by demolishing the rule of law in those few countries which can act as a partial model for their futures.  If you are passionate about helping “the oppressed of Africa”, why not go and live there, as I did.  Get to know the situation first hand and make some small contribution of your own to economic and social development)

Sorry about the rant.  I started to redraw some of the pencil sketches I was working on just before I moved from the Curriculum Development Unit to the University.  These were attempts to convert the hands-on experience of my 20s and 30s, into teaching materials for courses in Building which were offered as part of the secondary school curriculum.  While at the University I “taught the teachers” … in reality learning as much from the experience as they did.

Which brings us to the past few weeks.  After more than a year of constructing an intelligent digital model of Notre Dame de Paris as part of an international, voluntary group, I felt the need to think about church design in general a bit more deeply.  Put the work in context.

How to do that?  Has to be by drawing.  Make the hands busy and the brain will do it’s thing in the background.  The subconscious will churn away, processing all manner of visual and verbal data that will come popping back into consciousness, unbidden. at the most opportune and revealing moments.  The mind is a phenomenal machine, more than a machine I suspect, though I don’t believe in woo woo.

And so I have been sketching churches.  Mostly on my phone and based on random image searches on Bing.


From there I found myself motivated to tackle something smaller than Notre Dame and to shift back from the Gothic of medieval times to the Classical language of the early enlightenment period.  Hence this weekend, spent “BIM sketching” St Anne’s, Limehouse by Nicolas Hawksmoor: built just over 300 years ago (so closer to the present than it is to Notre Dame’s inception, in years at least)

I will do another post about that process.  For now an image or two.




Saturday, August 15, 2020


It’s November 2012 and I’m all pumped from winning the Parametric Pumpkin Competition for the second time.  That was my Arcimboldo style witch’s head … assembled from vegetables.  Zach Kron, who came up with that competition asked me to do a session on Vasari Talks, a series he was doing with Lilli Smith.  Remember Vasari?  I used it a few times.  The built in solar diagrams and wind animation were useful. 

They asked me to do a demo of the “wig-hat” which was the witch’s hair, assembled as a repeater using spring onions … was it a repeater?  Seems like the recording of my talk is no longer available on that link. 

After the demo, I showed a few images of other things I had done using the principle learned while making vegetables.  I wanted to assure people that my explorations were relevant to the “day-job” world of Architecture & Construction.  This is where I first developed my early concept model of Oscar Niemeyer’s Brasilia Cathedral: fully parametric, as they say.

I also showed a model of the Dubai Creek Golf Club, probably the best-known design by my boss, Brian Johnson (it features on the 20 Dirham note here in the UAE).  One of my first attempts at an adaptive component: three instances, one for each “sail-shaped” roof.


This is around the time when Paul Aubin and I started communicating directly with each other.  He was working on a Corinthian capital which totally blew my mind, but also challenged me to think about how I would approach this challenge. 

“How can we possibly standardise and parameterise all that variety ?  And even if we could, where would that get us?  The spirit of the Corinthian seems to live in it's infinite ability to be constantly re-invented.  How do you factor that into an equation?”

I the second half of the post I attempt a stylised version of Corinthian made from brass plate, cut and folded into shape. Designing directly in Revit. Of course in the good old days, there would have been a symbiosis of architect and artisan when conjuring up classical detail, both contributing their skills, experience and sense of proportion.  How should that collaboration play out in the digital era?



In the next post I attempt to take a leaf from Paul’s book and create a fully volumetric stone version of the Corinthian capital. It’s fascinating to compare Paul’s approach and mine.  He came at it very systematically, basing his work on Robert Chitham’s excellent book “The Classical Orders of Architecture”

I just jump in and start thrashing around, taking liberties and shortcuts wherever the mood takes me and feeling my way to an acceptable interpretation of the genre.  I was very concerned with “RIGS” at the time: arrangements of reference lines that can be resized parametrically.

There were several iterations before I arrived at my current system for mix & match, scalable classical columns.



The next post is quite interesting because someone has posted a Revit version of the Pantheon on LinkedIn recently.  He has taken it a fair bit further than I did.  I toyed with a couple of ideas for representing Corinthian here, including symbolic lines that only show up in parallel views. As usual I am trying to use Revit as my BIM pencil, and extension to my brain, a tool for better understanding how a building works: spatially, structurally, stylistically …



More rigs and more attempts to explore “the way we build”.  I had extracted a lot of mileage from a “Rectangular Rig” so the question was, would an extra dimension create new possibilities or would it simply complicate things.  The first set of explorations were good fun but didn’t produce anything that I regarded as a significant breakthrough.

At the end of the post I show an image of a Bavarian Baroque church.  I was looking for challenging geometry from our built heritage that might prove amenable to the techniques I had used to create vegetables.  I never got far enough with this model to test that idea out.  Would I be able to represent the free flowing curvature of the ceiling vaults in a convincing way?



December now, and an explanation of how I created my abstraction of Niemeyer’s cathedral.  I gave some examples of what happens when you play with the parameters. Vary the number of legs, the angle of slope, the heaviness of the legs in relation to the overall shape. 

Does this kind of “generative form finding” work better than the “artists eye”?  Stupid question perhaps.  All depends what you are trying to achieve.  Whatever too you decide to use: digital or analogue, computational or intuitive, rules based or touchy feely … you need to pay your dues.  If you want to achieve something worthwhile, first acquire a level of fluency with the chosen tools.



The first ever AUX in Dubai.  My session was about massing. “Concept design … clarity of thinking … strip away the irrelevant detail … can you capture the essence of the design problem?  … We need to use BIM tools as we would use a rapid pencil sketch”

Looking back, I’m really impressed with the way I prepared for this session, and the balanced structure I devised: a few slides, then a demonstration sequence, and closing with a longer slide show.  This was very early in my career as a public BIM personality.  I have come to realise that my contribution doesn’t always appeal to mainstream audiences.  So be it.  I get enough positive feedback to realise that I am doing something important and useful, and I’m doing it “My Way”. ...


I have always been somewhat ambivalent about Autodesk University.  The name is just a branding decision, I get that, but my idea of a university is much more open ended and exploratory that this industry convention.  The next post includes quite a lengthy rumination on the global politics of technology and the need to better integrate our heritage of intuitive hand-crafted ingenuity with the digital sphere that offers so much power.  Power can cut both ways. If it doesn’t mesh with our traditions.

“The main reason I'm hooked on Revit and BIM has nothing to do with ROI or clash detection.  It's a better way to draw.  And drawing has nothing to do with lines, arcs & circles.  Leonardo wasn't thinking "now I'll draw an arc".  He was exploring how the human body works.”



And so to Xmas 2012, and the “Mush” part of my title.  I figured out an approach to making Arabic patterns that will populate divided surfaces.  This allows you to create Musharabiya Screens that twist and curve.  Creating each new curtain pattern family is a bit tedious, but once you have a small library of these, it’s very easy to create screens of different sizes, shapes and proportions. 

Since then I have developed other solutions: scaling patterns up with the Planting Category hack for example.  But maybe I should give this one another run around the block.  What would I do with it now, almost 8 years later?


Wednesday, August 12, 2020


This one dates back 2 years to a discussion on the Volterra WhatsApp group.  I had met Mark Dietrick for the first time a couple of months earlier, in Tuscany at the Reality Capture workshop he was instrumental in organizing.  I don’t remember just what input he was asking for and what my contribution was, but I did a small exercise to illustrate a method which I will attribute to both of us.

This is also in response to a video that Paul Aubin posted with a cute little method for “faking” a legend for colour-coded furniture plans (or any other category)

There are two parts to the method.  The second part involves sorting room types into rows so their areas can be totaled.  I think that was Mark’s concept, but my memory is a bit hazy.  Anyway, I will come back to that.  The first part is a way of doing a “legend” for a coloured room plan that incorporates a column for areas.

The “legend” is actually a schedule.  Column 1 is the built-in Image parameter that was added to Revit some years ago.  Normally we might use that for something like washroom fittings to display a thumbnail image of the specified item.  In this case I loaded small coloured squares from a folder.  I created these squares using Photoshop, just 150x150 jpegs with specified RGB values. 

You need to match these RGB values to the ones used in the colour scheme for the plans.  Once you have assigned them to a room, they will show up in “Manage Images” and you can easily assign them to as many rooms as you need, via the popup dialogue.


In case you need to reserve the built-in Image parameter for some other purpose, it’s easy enough to create a new Project Parameter of the Image category.  In this case, I called it Colour Code 01 and put it in the Identity Data group along with the original Image parameter.  Don’t know of any way to move this up in the order.  If it was Furniture you could open a family up in Family Editor to do that, but being a system family, Rooms don’t open in Family Editor.

Not a big deal. This time I have used the original four images that I created, which match the first 4 colours that Revit automatically assigns to a Colour Scheme.

Let’s move on to the second part.  We want to have a separate area column for each category of room.  This is done by creating new, custom Area parameters for the Room Category.  I called these “Area-a”, “Area-b” etc.  We can use an “IF” formula to populate these columns.  If the condition is true, copy the automatic room area to the custom field.  If it is false set the custom field to zero.

I used an Integer parameter called “Dept Index” to achieve this.  So the formula takes the form: IF(Dept Index = 1, Area, 0)  For each value of Dept Index the formula is adjusted to match.


To coordinate “Dept Index” with “Department” I created a Key Schedule for the Room Category.  Believe it or not, I had never really used Key Schedules before, certainly not on a regular basis.  First of all you choose a family category (Rooms) then you choose to “Schedule Keys”. This will generate a “Room Style” field which you can use to control other fields, in this case “Department” and “Dept Index”.

If you decide to create another Key Schedule for Rooms, those two parameters will no longer be available.  You can’t have a parameter being controlled by two different fields.  That would lead to conflicts. 

In the Properties dialogue box, any parameters that are controlled by a Key Schedule are greyed out. I guess you might have a situation where you want to have two keys for Rooms, let’s say “Dept Style” and “Finishes Style”.


A schedule with multiple columns where most of the boxes contain a “zero” can be very confusing to read.  Too much irrelevant information.  To counter this, I came up with the idea of using “Conditional Formatting” to grey out all the zero cells. 


Paul used the example of a furniture plan, so I decided to test that example.  But first of all I wanted to generate a basic reservoir of colours that could be used “for ever more”.  These are all basically “Pastel Shades” … because you don’t want the colours of rooms or furniture to dominate over the walls that contain them.  I guess I might want to create another, darker set at some point that can be used for solid objects, maybe for walls of different fire ratings, acoustic or thermal insulation values. 

But step one is a set of 57 pastels starting with “lilac” and finishing with “pink”, plus five shades of Grey.

The naming convention uses a number to keep them in order, plus a RGB value to aid with setting the colours in a “Colour Scheme” or a set of “View Filters”

To colour the furniture I set up three view filters, simply named “style 1”, “style 2” & “style 3”.  These are based on the “Comments” field which sits next to the “Image” field.  At the moment these are coordinated manually, which is easy to do via a schedule.  I guess you could automate that with Dynamo if you really want.

In my current iteration the schedule is formatted as a simple legend, but it would be easy enough to add a quantities column.  You could also create separate columns for the different types of furniture perhaps so that you could see the distribution of styles for Sofas, then Tables, and so on.

Hope you found this helpful.  You can download my pastel images from the link below.




Sunday, August 9, 2020


A couple of weeks ago The Revit Kid (aka Jeff Pinheiro) got in touch and asked me to appear on his podcast “BIM after dark” to showcase the Notre Dame model.  The podcast took place on Thursday night.


I probably should practice looking at the screen while I think.  Seems like my eyes skew “up and away” when I’m thinking 😊.  Also note the face masks and the Zimbabwe flag decorating the back wall of my apartment.

In preparation for this session I put some time into annotating and organizing the sheet set to tell a story.  The grid studies sheet was already there.  I just added some explanatory text.  How many weekends did I sped puzzling through the reference material, comparing measurements and deciding whether to adjust the model to a new grid?  It went through at least 3 iterations, if I remember right, but we now have something that reflects the size of each bay quite closely, and maintains the basic relationships, but keeps the setting out orthogonal.

This sheet serves as a record of how that works.

Alfredo made a very nice cutaway “view” for his AU session last year, and I have updated this with a few annotations.  It serves well as an introductory sheet.  It was created by placing three views on a sheet and carefully adjusting their section boxes.  You have to place the views in the right order to get them to “overlap” convincingly.  “Send to back” only works with 2d elements.

The upper floor plan.  I love the way this sheet has turned out.  It has developed slowly over the months.  The elevations were added to set up “tasks” based on starter families.  The windows were tagged with their family names, and those families placed in a series of folders along with reference images.  Francois has risen to the challenge of developing these elements, and made excellent progress, though not yet complete. So the windows are now tagged with codes (Type Mark) which refer back to a window types sheet (Legend)

While preparing for this talk, I added some notes and photos so that this sheet now gives a splendid overview of the Tribune Galleries, and of the strengthening works around the crossing by VLD.  I puzzled over the reason for those non-standard bays, from the time we first started the model.  At one time I had decided it was a device to disguise the much wider bay between grids 8 & 9.  The full sequence of events and structural logic has only dawned on me in the past couple of weeks. 


At this point, I took my first detour into family editor.  These small flights of steps occur in two places at the ends of the Tribune Galleries.  In a way they are like a straightened out spiral stair.  But they are also precursors of the “cantilever stair” which became so common in the domestic architecture of Europe from Renaissance times until quite recently.  More accurately called a “torsion stair” each stone tread is supported on 3 of its corners: two embedded in the wall, and the third resting on the step below.

I do love making items like this in Family Editor.  Nothing fancy, just extrusions and a couple of parameters … one level of nesting.  But it’s a wonderful way to understand something that catches my eye in the work of builders past.


I’m rather proud of the next sheet, which combines a large central perspective view with smaller plans and sections, plus a couple of small internal camera shots.  This serves to illustrate some complex spatial relationships relating to an enlargement of the clerestory windows that was undertaken almost as soon as the original design was complete.  The story is further complicated by changes that were made by Viollet-le-Duc in the nineteenth century: strengthening the crossing to take the weight of his new spire.

For me, this sheet exemplifies the discovery process that takes place on a collaborative historical investigation like Project Notre Dame.  Week-by-week we gradually tease out a story that spans several centuries of human experience.

Segue to the vaults sheet, by noting those vaults on the previous sheet that are higher on the outside face.  This is a feature of ribbed gothic vaults that I had not been aware of before modelling Notre Dame.  Now, of course, I see it everywhere when I visit old cathedrals.  Alfredo took the adaptive route (what I call “Point World”) and I took a quick look at his 8-point vault, used in the Bell towers.  By way of contrast, I then opened up my attempt to use the traditional family editor to create a flexible 4-part vault with the ability to cover rectangular bays of different sizes, and to selectively lift the outer arches on any of the four sides. 

There are pros and cons to both approaches of course, and I think there is still room for improvement in the way we are representing the vaults.  That applies to most aspects of the model actually.

Jeff passed on a couple of questions from the chat, but I didn’t get to read through the comments till next day.  Interesting feedback. 

On the right you can see drawings by VLD explaining a method for constructing the vault infill between the arched ribs.  Fascinating to me as a former bricklayer.


I decided to add jpegs to the elevation sheets. In the process I noticed, for the first time, that we have two old photos taken from a similar angle, one just before VLD restored the spire, and one shortly after.  Looking closely at these, the changes he made to the windows around the crossing are very clear, also the addition of clock faces, and the small stone pyramids capping the spiral stairs.

West End Story … a study sheet for the West End with its Bell Towers and King’s Gallery.  The levels are quite tricky … some tweaking of View Range parameters required.  Assembly of this sheet was the final stage in a long process of understanding how these various spaces fit together; the galleries, balconies and passages that link them together.

Last of the Family Editor detours, featuring the double-nested planting hack and imported mesh geometry with hidden edges.

Alfredo had started to set up a sheet for the Rose windows. I adjusted the scales and added a strip on the right-hand edge.  Legend views of Marc Zappia’s contributions, a couple of notes and one of VLD’s fantastic drawings.

I managed to squeeze in a quick tour of the model in Enscape3d.  For speed I had exported and Enscape executable and had it open in the background.  Imagine a world before Enscape! 

I didn’t have time to show all the sheets.  The sections are not quite complete but starting tell their stories quite nicely.  But I think we covered enough ground for one session.  Clearly there is a lot of potential interest out there in the kind of work we are doing.  The power of “the BIM pencil” to support curious minds in their attempts to enquire more deeply into our built history.

So once more, thanks to Jeff for setting this up and being such a genial host.  I don’t think I have a future career as a YouTube star, but perhaps I could do a couple more of these kinds of live tours.  Notre Dame has more secrets to offer, and we could always go on to explore Project Soane.

If you have made it so far, I can offer you a small reward.  Follow the link to download a PDF copy of the current sheet set.  Far from final, but worth a look, I think.