Wednesday, July 17, 2019


I wonder if I will walk along the eaves of Notre Dame one day.

The ground floor windows that illuminate the many side chapels are represented by simple placeholder families right now. In reality, many of them have a triangular “gable” I think this is a nineteenth century addition. For some reason the windows on the North side of the nave don’t have this feature. Maybe they ran out of money, and the side that is visible from across the river took priority.

What is it about the spire?  Primeval symbol ?  or just a landmark, visible above the rooftops? Certainly, it manages to balance a tower-heavy mass and to offset the solidity of masonry with a sinuous spikiness. I wonder what the medieval spire was like before its state of dishevelment justified Viollet le Duc’s redesign.  So far I haven’t come across a drawing that shows this.

Marcel’s modelling is shaping up pretty well now, lego men stepping up the roof valleys where it straddles the crossing and crockets arrayed up eight ridges of the “witches hat”  Lots of detail that could be added, but it’s compatible with the rest of the model fat the moment.

Two of the South East window bays are actually portals connecting the chancel to the sacristy. So I decided it was time to rough out this addition which was also an innovation of Viollet le Duc. In contrast to the overall symmetry of the cathedral it is an irregular form. But what do I make of an annexe for storing relics which has evolved into a tourist exhibit.

Religion has deep roots. Hunter gatherer bands lack the rigid dominance hierarchies of our primate relatives. This seems to have been achieved by shunting alpha and beta males to the realms of fantasy.  This reduced the hostility between groups creating a positive selection pressure. Groups that told stories about common ancestors and kept skulls in niches survived famines by collaborating.

But if the sacristy is a remnant of our origins on the African savanna, does that make tourism the modern equivalent of a pilgrimage? Is that how we now relate to our ancestors, by traipsing around museum exhibits?  For my part, I prefer the “active learning” approach we are pursuing with Project Notre Dame.  So maybe the Revit model is our “sacristy,” the sacred relic that we are preserving for the benefit of the human tribe.

Be that as it may, buildings require maintenance, and access routes above ground need safety rails. And rails need posts for stability.  So I set about dividing the railings around the various eaves levels into bays and placing simple rectangular blocks on the grid lines to stand in for the more elaborately sculpted posts that exist in reality.  There are some alignment issues where these sit on top of pilasters that are part of the flying buttress families, but we will sort that out later on.

In the corner where the South Triforium gallery meets the Bell Tower, I stumbled across another surprise.  The roof pops up to a higher level.  This is reminiscent of the junction with the Transepts where it also pops up as it turns the corner.  It's kind of hidden under the flying buttresses and I only spotted it in one grainy black and white photo.

I think there are probably unanswered questions here, but for the moment let's just take note of the vault over this bay, which is much higher on the outside than the inside, allowing for an extra tall window.  When you know what to look for this taller window is evident in one of the panoramas on the TruView free site, but I had looked at this several times before without realising what I was seeing.

There's a great little sketch by Viollet le Duc which shows what's going on in section.  Actually that's another revelation, discovering the depth of his scholarship and talent.  I learnt such a lot when I was working on Project Soane: a new deep insight almost every weekend .. and Project Notre Dame is headed in the same direction.

As an offshoot to discussions around “how to get hold of a point cloud” we came across a fascinating website called Mapping Gothic. This has a lot of useful information about a huge number of cathedrals across both France and England, including some splendid 360 panoramas of Notre Dame de Paris.  Highly recommended.  University Art History departments are doing some splendid work, all we need to do know is introduce them to the benefits of BIM 😊

Since the last post we have received a huge influx of offers to assist in various ways.  I am truly humbled by this response and we have started to devise systems for enabling a “content creation” role in parallel to, an in support of the live work on BIM360.  I think we will also need to have a couple of people who focus on setting up views and sheets, annotating, developing and enforcing naming standards, etc.  

This project has developed very rapidly in an almost “accidental” fashion and we are pretty much making it up as we go along.  If you come across our VR experiences at the BiLT conference in Seattle, please realise that this is very much a “Work in Progress” and we are fully aware of the many shortcomings and inconsistencies.  

As for the “Content Creation” role, we have set up a cloud storage are on the Mega NZ platform.  If you get an invite, please accept it, install MegaSync for Windows and synchronise the Incoming Share you received to a folder on your local drive.  That way, you will get updates and reorganisations that will inevitably take place over the coming weeks.

So that's it.  The model is moving forward on several fronts, and the community we are building around the collaborative process is growing rapidly.  Alfredo & I have been accepted as speakers at AU in November.  We have started to explore the VR potential.  Living in pretty interesting times.

Monday, July 8, 2019


The model as it was at the beginning of this post 

There is a network of maintenance access routes that we are just beginning to understand. The next image was posted on LinkedIn just over a week ago and has had more than 26,000 views. It shows a semi-concealed viewing platform between the two towers, directly above the organ loft. Inside the towers on either side are massive wooden frames to support the church bells. Organ music and the peals of bells: the sounds of medieval Christianity. I digress. 

From here you can pass briefly through the corners of the roof void to emerge at eaves level high above the nave on either the North or the South side. With the steep roof on one side, and a stone balustrade on the other, you can walk along a gutter / access gallery, all the way to the junction with the Transepts 

At this point the route gets complicated, and an element of guesswork creeps in. It’s quite clear that the Triforium Gallery (1) is connected to the access gutter (2) by a spiral stair (3) From here it seems likely that there are short passages within the thickness of the wall leading to galleries that cross below the rose windows (North and South) The interior galleries surely have a door at each end, but I am yet to spot the access to the balustraded ledge across the outside. A hinged panel in the glazing perhaps?  

In the last couple of weeks Paul Aubin has done some more work on the flying buttresses. The ones that support the vaults over the nave are now looking really splendid and clearly show the fascinating, steeply sloping channels that funnel water from the high eaves, through cute little pavilions into projecting gargoyles.  

I spent a day or so taking mesh-modelled statues, sourced and processed by Russell Fuller Hill, and inserting them into my placeholder families along the West Front. Two angels either side of a Madonna and child stand on a balcony at the base of the Rose window. Further out to the sides are two more figures also on tall bases.  

One level down is a continuous row of figures with crowns on their heads, standing within an arcade, between slender columns. There are about 30 figures, all different, but although the mesh models are much closer in spirit to the stone originals, they are far from being an exact match. So we are moving from identicallego-man” placeholders to an impression of carved statues in historic dress with variety as you move along the row. But in fact there are just three different versions alternating. 

First pass at the eaves detail had been a plain wall standing on an in-place sweep. To take this to the next level I placed a thin floor on top of the sweep and used this to host a railing. For now, the railings are continuous and I’m using a railing I developed for the West Front.  Eventually there should be at least 4 different patterns of stone balustrading in the model. We are just feeling our way gradually towards a more accurate representation. 

Alfredo has done a great job of modelling the North and South rose windows and in the process tackling the important issue of maintaining clarity at different view scales.  At a glance these windows seem to be the same, but on closer inspection they are completely different: number of segments, whether there is a pane of glass or a mullion in the vertical centre position, etc

He followed up this work with a very well constructed blog post. I’m using some screen grabs from that here, and you have to say we are starting to get some nice crisp documentation from the model now. Check out the post at this link.  

I set up a series of sheets several weeks ago. and the model is taller now than it was then.  This is partly because the bell towers are taller than my original guess, but mostly because Marcel has added the spire.   Those sheets are looking very crowded now, and the top of the spire is chopped off.  I’m starting to think that we need to double the number of sheets and give the individual views a lot more air.  

I would really like to add some annotations soon also, but that requires a bit of thought. This is BIM and I don’t want to use text. We need to decide which elements to use and which parameters can host historical information in a structured way.  

Or maybe I will just start doing it, and learn from my mistakes. It seems that my role on the project is to be the guy who rushes ahead and doesn’t mind making mistakes. Paul and Alfredo, on the other hand are carefully selecting elements that they can develop in a more systematic manner. Marcel I think is somewhere between these two extremes in his work on the roof trusses and the spire.  

Russell, so far is playing the role of back office support, feeding us with content to use in the model. I think we will need more people doing that kind of work.  

So that’s where we are right now after recent work on  
  1. Statues 
  2. Access galleries  
  3. Buttresses 
  4. Rose Windows 
  5. The Spire