Greyfriars Reimagined Podcast | Episode 2 – Mark Gardiner (with transcript)

In today’s episode, Alex is talking to Mark Gardner of Lincoln University about digital scanning of heritage buildings. This episode was recorded in early 2021. This podcast is part of Heritage Lincolnshire and City of Lincoln Council’s Greyfriars project, which aims to bring the Greyfriars building back into use. This project is funded by the National Lottery Heritage Fund, the Architectural Heritage Fund, the Pilgrims Trust and City of Lincoln Council.

Episode Transcript:

[Music – ethereal female choral singing in Latin. Ecclesiastical style]

 Laura Dunham

Hello all, welcome to the Greyfriars Reimagined podcast, where we explore the past and the future of Greyfriars Lincoln, one of the oldest Franciscan Friary buildings in England.

This podcast is part of Heritage Lincolnshire and City of Lincoln Council’s Greyfriars project, which aims to bring the Greyfriars building back into use.

This project is funded by the National Lottery Heritage Fund, the Architectural Heritage Fund, the Pilgrims Trust and City of Lincoln Council.

In today’s episode, Alex is talking to Mark Gardiner of Lincoln University about digital scanning of heritage buildings. This episode was recorded in early 2021.

[Music – Violin and harp music accompanied by female singer singing in Latin. Sounds medieval in style]

 Alex Harrison

So, welcome to today’s episode of The Greyfriars Podcast.

I’m here with Mark Gardner from the University of Lincoln today.

My name is Alex. I’m currently studying a Masters at the University of York in building conservation, but I’m originally from Lincoln, which is why I wanted to get involved with the project.

So hi, Mark, if you could introduce yourself.

 Mark Gardiner

I’m Mark Gardner and I’m an associate professor at the University of Lincoln and by background, an archaeologist. But one of my roles in the University of Lincoln is as director of Lincoln Conservation, which is a very broad conservation practice, so we do all sorts of things from architectural paint research, but one of the things that I’m particularly interested in is digital heritage and we work with laser scanning. We work with laser scanning buildings, for example, laser scanning objects, and because I’m also a building archaeologist, I’m particularly interested in the application of laser scanning to recording buildings.

 Alex Harrison

That’s brilliant, thank you very much.

Building on that, you are laser scanning at Greyfriars for Heritage Lincolnshire. So, what sort of is laser scanning and how can it help at Greyfriars?

Mark Gardiner

Well, the real advantage of laser scanning is that it’s a way of recording very precisely and fairly quickly all the dimensions are building, so in the past when I first started, we wanted to record a wall face or you wanted to record a plan, you got out your tapes and you had a drawing board and you drew every stone and so on and it was a very long and very laborious business. It took a long time.

Laser scanning, you know, immediately takes away all that and it does it much more precisely than we were ever able to do with hand methods.

So what you’ve got is essentially a scanner which is set up on a tripod and it sends out what’s called a point cloud, a sort of cloud of laser points, which is they’re transmitted from a from a rotating mirror, so it records all the way around. You know everything around.

You can set it to just look at building or usually you set it to look at the whole surroundings because it helps with the alignment of the scans. And it records a series of points very, very precisely, so you know, within millimetres.

Mark Gardiner

And in addition to that it creates, you take photographs and what in effect it does is it drapes those photographs over a digital surface. So, it’s like sort of in pressing something onto a digital surface, so you’ve got an absolute direct picture of a wall or you can look at building.

Now, the advantage in Greyfriars, but Greyfriars is a bit complicated because it’s a long thin building, so a laser scanner only can record what you can see in front of you. So what you have to do is you have to set the scanner up in a whole series of positions opposite the building opposite wall of the building and work your way along.

And then you digitally join afterwards, you digitally join those scans together so the computer says, well, I recognize that window, I’ve seen that window in another scan. I can put those scans together in some sort of relationship. So there’s a certain amount of post scanning processing which goes on.

Now what you end up with? Well, you end up with something which is which is really useful. What we’re particularly interested in at Greyfriars, two things.

First of all, you can create a model of the building. It was digital model, so it’s like something you can rotate and you can turn upside down and you can look at it from any direction at all. But so that’s one of the things that we’re going to going to produce for Heritage Lincolnshire.

The other thing that we are particularly concerned about is to produce for the architects and the people who are going to work on this building is orthophotos. And an orthophoto is different from a normal photograph because normal photographs are you know, create this sort of optical effect at the edges where the edges are sort of slightly more distant.

An orthophotograph is like a, uh, a photograph, which is like a plan or a map. So, if you measure the distance between one stone and another stone on an orthophoto, that is what it would be like in real life.

So, we can produce orthophotos of the wall elevations. So it’s a marvellous tool and we can do this relatively, I say relatively, simply.

Alex Harrison

And that’s great that you can do it simply, and I must say I did a bit of buildings recording in my first year as an archaeology undergraduate, and it was a very long day of recording masonry walls at a parish church in Yorkshire, so it’s great that you can do it so, like I say, relatively simply with the lasers.

And with Greyfriars, will you be facing sort of on the interior or exterior or both?

 Mark Gardiner

We’re doing we’re doing both actually. We’re going to do the exterior, and then we’re going to take it inside, and we’re going to do the interior and you can actually join those points up and what you have to do is you have to scan your way in so that the laser scanner is both looking outwards and inwards and it can connect up the interior faces and the exterior faces together.

Now there are always problems, Because you actually you can’t scan through a window because glass refracts and reflects the laser light, so that’s always poses a little problem. So you actually have to go through a clear space through a doorway. And the more doorways that you can get, and there’s only one in Greyfriars for the basement. The more doorways you can get, the more precisely you can connect the inside and outside faces. But we’ve done that before and it works quite well with buildings.

And so we are going to produce elevations of both the undercroft the ground floor of the building at Greyfriars in in the interior and then go up and do the first floor.

The undercroft a bit difficult because you’ve got all sorts of different faces. It’s got these stone vaulting stone ribs of vaulting, and which support the 1st floor and because you’ve got lots of little faces which you can’t see from anyone position, it would be quite a complicated job to actually set up the scanner in lots and lots of different positions so we can see every different face of the wall. But we’re not going to do that because essentially the task at Greyfriars is to record, on the interior, is to record the wall faces. So, we’re not going to worry too much about the vaulting.

And on the 1st floor, we’re not too worried about the roof, although the roof is very, very interesting because it is a medieval roof.

 Alex Harrison

Yeah, that’s brilliant. So, it’s great that you’re doing the inside and exterior. I was wondering because sort of the whole Greyfriars project is orientated around sort of a sensory experience. They want to get actors in, you know, as we’re as we’re allowed to with restrictions, etc. So, I was wondering how conducive is the laser scanning to aiding sort of spatial and sensory analysis?

 Mark Gardiner

Well, once you’ve got this model, digital model of the Greyfriars, there are all sorts of possibilities, places that you can take it, things that you can do with it. So, you know at a very, very simple level you can take a model of the building and you can put it on the web so there’s a website called Sketchfab and you can reduce the size of your digital record, put it on Sketchfab and then people can come and look at it, look at the building. Look at either the interior or the exterior of the building and they can see what it’s like.

Those pictures those digital models can be embedded in a website, so it’s a way of you know bringing people into the building. But there are all sorts of other possibilities of what you can do once you have this digital model. You can use it for augmented reality or virtual reality, but that’s another stage beyond the sort of thing that we’re doing, but it’s a possibility. It’s a way, a thing that you can do, perhaps for the future.

 Alex Harrison

Now, and I mean that’s extremely exciting prospect mapping, sort of the interpretive side with what you’re doing. And I know there’s a lot of sort of expert volunteers who are very familiar with Greyfriars, so I’m sure it’ll be great for them to see it at home on their screens, like say on Sketchfab and websites like that.

Uhm, I think you’ve pretty much covered everything we would like to know about laser scanning at Greyfriars. If you’ve got anything else you think important that I might have missed in my questions, and please let us know.

 Mark Gardiner

Well, perhaps, perhaps I could say a little bit about, I mean, you’re a building archaeologist, Alex; I’m a buildings archaeologist. And of course, you know people might wonder why are we interested in recording it stone by stone? Why is it so interesting?

But of course, a building such as at Greyfriars has got a long history not just of when it was put up, but also it was modified in the Middle Ages. It’s then being modified on number of times, since they’re all its various uses as school and as a museum latterly.

So it’s got this history of changes to the fabric which have been made and the only way that you can pick that history is really by very very detailed analysis of the fabric and this is really a sort of important first stage, because Greyfriars is a complicated building, indeed quite a controversial building.

What exactly it was used for? You know we do ever solve these problems is really by this very, very careful analysis of the buildings.

And I’ll just say one other thing because I haven’t really talked a little bit about what one of the things that laser scanning can do, because once you’ve created a digital model, you can do all sorts of really fun things with it.

For example, you can slice through the building, you know digitally not in reality, so you can just take a cross section across the building or along the length of the building, so it’s not just elevations, you can do it in the interior. You can cut through the building.

So, you know it’s the sort of things that one can do is sort of almost limited by one’s imagination, because once you’ve got this digital model well, how do you want to cut it up? How do you want to slice it? Do you want to slice it horizontally? Do you want to slice it vertically? And so on.

So, there are all sorts of really fantastic possibilities. You know you talked about, your experience you know hand drawing stones. Well, this takes it to another level because suddenly you’ve got this tool which allows you to record absolutely precisely to within millimetre accuracy, our buildings in a way which you and I you know wouldn’t think of doing because we’d have to hand draw it.

So, it’s a very, very exciting tool, really.

 Alex Harrison

Well, yes, admittedly, my first-time drawings of the stones probably were relatively inaccurate. It’s great that we can get that degree of accuracy with it, and like you say, the means of what we can do with it is incredible.

So, I think that just about comes to the end of this podcast Mark thank you very much and hopefully we could maybe get you back after we’ve done the laser scanning and maybe talk further about its uses, I suppose.

That’s brilliant, thank you very much.

 Mark Gardiner

Great, thank you.

[Music – Violin and harp music accompanied by female singer singing in Latin. Sounds medieval in style]

 Laura Dunham

Music was performed by soundLincs and Hildegard and recorded at Greyfriars.

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[Music, continued from previous – Violin and harp music accompanied by female singer singing in Latin. Sounds medieval in style]