1
00:00:08,534 --> 00:00:10,977
So now that we ...

2
00:00:11,658 --> 00:00:13,270
... I'm a programmer ..

3
00:00:13,972 --> 00:00:15,581
... I hope that we're going to get a bigger soon ...

4
00:00:16,302 --> 00:00:20,161
We specialise in masonry. Masonry bridges in particular.

5
00:00:21,080 --> 00:00:24,773
We do a few other bits and pieces, but the core is basically bridges.

6
00:00:25,174 --> 00:00:29,281
We're always looking for new ...

7
00:00:29,563 --> 00:00:31,349
Sorry!

8
00:00:31,349 --> 00:00:39,302
...

9
00:00:39,830 --> 00:00:42,212
Hopefully that doesn't trouble.

10
00:00:44,316 --> 00:00:53,036
So I think we're looking for ways to understand damage better, and in masonry that is an interesting task.

11
00:00:53,535 --> 00:00:56,819
And in the last couple of years we've done a lot of work on developing photogrammetry

12
00:00:57,183 --> 00:01:02,250
which we believe has the potential to transform inspection and assessment of historic bridges ...

13
00:01:02,788 --> 00:01:04,458
... and all masonry bridges ...

14
00:01:04,458 --> 00:01:07,682
But really all masonry bridges are historic bridges.

15
00:01:10,872 --> 00:01:16,098
I don't have to tell most people here, I think, about photogrammetry, so I'll cut out all my usual slides.

16
00:01:17,401 --> 00:01:20,171
The basic process is you take a lot of photos, with lots overlap ...

17
00:01:20,736 --> 00:01:23,389
... compress them down into a model and then you profit from the results

18
00:01:24,466 --> 00:01:28,058
Reality is obviously a bit more detailed.

19
00:01:30,348 --> 00:01:33,595
I'm not going to talk about processing a basic trick that we have here ...

20
00:01:33,595 --> 00:01:36,232
... is big workstation and reality capture. Which is fantastic.

21
00:01:38,620 --> 00:01:49,486
Taking photos is more of an issue, and how you get information out of the data that we produce is the second part.

22
00:01:51,100 --> 00:01:52,280
A couple of case studies.

23
00:01:52,650 --> 00:01:59,182
Pontypridd Old Bridge was built in 1750.

24
00:01:59,358 --> 00:02:02,150
It was the fourth attempt that Williams Edwards made.

25
00:02:02,475 --> 00:02:05,500
He was given a 7 year contract to cross the Taff at this point.

26
00:02:05,739 --> 00:02:13,064
The first attempt was a 3 span washed out by floods.

27
00:02:13,317 --> 00:02:16,619
He thought, well sod that. if I'm going ... to go in 1 step

28
00:02:16,951 --> 00:02:22,327
That one, the centering collapsed before the bridge was finished.

29
00:02:22,590 --> 00:02:26,828
Not being put off, he did it again, did the centering a bit better.

30
00:02:26,891 --> 00:02:28,262
Successfully structured the centering.

31
00:02:28,262 --> 00:02:29,760
Six weeks later the bridge collapsed.

32
00:02:29,760 --> 00:02:31,931
And it collapsed in a particular way

33
00:02:32,151 --> 00:02:34,240
with the crown bursting upwards and the sides going in.

34
00:02:34,936 --> 00:02:39,571
So he then gathered a little bit more money together from the gentry of the area

35
00:02:39,820 --> 00:02:44,323
who must have been quite ...

36
00:02:44,613 --> 00:02:48,442
... he must have been quite compelling, or maybe it was the fact that he was a well respected preacher.

37
00:02:48,715 --> 00:02:51,079
Well he must have thought so anyway.

38
00:02:51,371 --> 00:02:55,459
He gathered these transverse tubes at the sides of it where it's out ...

39
00:02:55,718 --> 00:02:58,775
... and if you look at the top of it you'll see there's a partition ... at the top ...

40
00:02:58,984 --> 00:03:01,277
... and it's been there since 1786.

41
00:03:03,519 --> 00:03:07,783
100 years later they built this bridge along the side, that's been widened since.

42
00:03:08,073 --> 00:03:10,888
And now it runs to about half a meter from the circle ...

43
00:03:11,202 --> 00:03:17,213
So since 1850, or it seems, the south elevation ...

44
00:03:18,683 --> 00:03:23,654
Capturing photographs of this, what we're aiming to do is to get set sub-millimeter detail from the whole structure.

45
00:03:23,918 --> 00:03:30,141
It's big. It's 43 meter span. It's all rubble masonry, basically lots of roughness, lots of detail.

46
00:03:30,424 --> 00:03:32,975
The crown is about 10 meters off the water.

47
00:03:33,512 --> 00:03:40,247
Victoria Bridge is very close, which ...

48
00:03:40,984 --> 00:03:47,193
And at least there was a ford here, so in the driest summer in recent years it was certainly possible walk backwards and forwards underneath.

49
00:03:49,933 --> 00:03:52,745
And we ended up with 14,000 photos.

50
00:03:55,556 --> 00:04:02,634
That's taken straight from reality capture. And reality capture can take 14,000, or indeed up to 30,000 quickly photos.

51
00:04:03,563 --> 00:04:05,652
And align them.

52
00:04:06,117 --> 00:04:10,464
30,000 took me within a gnat's whisker of 256gb of memory.

53
00:04:12,327 --> 00:04:15,635
But it just does it.

54
00:04:20,307 --> 00:04:28,552
And you finish up with a model that allows you to step back and look.

55
00:04:28,811 --> 00:04:36,313
This is the south elevation. No-one has seen that for 170 years.

56
00:04:41,462 --> 00:04:43,991
In this view ...

57
00:04:44,521 --> 00:04:48,305
... 5 million triangles with a very high detailed texture that ...

58
00:04:48,897 --> 00:04:54,453
... mesh means that the texture is just slightly blurred on these rock surfaces.

59
00:04:55,360 --> 00:05:02,604
But we can zoom in and see cracks, and we can see details that we wouldn't really understand without the photographs.

60
00:05:03,036 --> 00:05:07,792
... for bridge inspection is much a detailed photograph site as issue here.

61
00:05:08,696 --> 00:05:09,894
Forced out.

62
00:05:13,248 --> 00:05:17,631
And so being able to understand that damage in context is pretty good.

63
00:05:19,895 --> 00:05:25,582
Being able to read the full photographic elevation of light to measure things.

64
00:05:26,924 --> 00:05:28,535
And we can zoom in to have a look.

65
00:05:33,234 --> 00:05:36,095
For some reason, it's not quite as good on the software, which is annoying ..

66
00:05:36,586 --> 00:05:38,551
.. but this allows you to see ...

67
00:05:38,811 --> 00:05:41,927
... it's still pretty good. You can see individual bits ...

68
00:05:45,168 --> 00:05:47,566
A bit on collection.

69
00:05:47,711 --> 00:05:49,341
We don't use drones.

70
00:05:49,341 --> 00:05:55,644
We don't have the scale to justify having the the utilisation that justifies the licensing costs.

71
00:05:55,644 --> 00:06:00,156
And anyway, I've yet to come to a bridge and find that half of it is only accessible to a drone.

72
00:06:00,610 --> 00:06:05,357
No trees. There's not a bridge next to it. It's next to traffic ...

73
00:06:05,794 --> 00:06:07,597
It will be useful for the some bits of it ...

74
00:06:07,984 --> 00:06:09,583
.. but we don't have to deal with this stuff anyway.

75
00:06:10,147 --> 00:06:15,096
So there we are ... standing in the river we've got some mud weights attached to the bottom of the pole for balance.

76
00:06:15,096 --> 00:06:17,801
And we can get it to about 8 meters.

77
00:06:17,801 --> 00:06:20,889
Different bridge, and we can stick it out over the side.

78
00:06:20,889 --> 00:06:22,196
...

79
00:06:23,927 --> 00:06:26,515
And we have camera rigs.

80
00:06:26,767 --> 00:06:31,138
So this is set of Sony QX1 cameras all strapped to a 6 meter beam.

81
00:06:32,179 --> 00:06:36,520
The triggers are powered on a wire so they trigger almost constantly ...

82
00:06:37,234 --> 00:06:42,042
... they're carbon batteries, so there's always one that's running out of battery.

83
00:06:43,345 --> 00:06:46,179
You can't take it in and change the battery if it's tied a beam.

84
00:06:47,458 --> 00:06:51,094
... Here you could walk into the swinging ...

85
00:06:51,662 --> 00:06:57,241
... rigged up the Sony to the side ...

86
00:06:57,854 --> 00:06:59,690
And why bother? It's a lot of effort. But ...

87
00:07:01,247 --> 00:07:05,929
The ability to zoom in and see that detail, and then step back and see where it is.

88
00:07:05,929 --> 00:07:07,896
I keep doing that in the office ...

89
00:07:07,896 --> 00:07:10,098
... where it's warm ...

90
00:07:10,265 --> 00:07:12,120
It's just unnatural.

91
00:07:12,894 --> 00:07:14,895
The problem is we get a lot of data.

92
00:07:14,895 --> 00:07:19,243
We don't need the data. We're looking for understanding.

93
00:07:19,342 --> 00:07:21,031
Just having the model is a step forward.

94
00:07:24,455 --> 00:07:28,923
We have a point cloud. You've got a vast amount of data ...

95
00:07:29,233 --> 00:07:33,203
... you can convert that into a mesh, and bring the data level down and get more access.

96
00:07:33,515 --> 00:07:36,779
Photogrammetry gives you a bit of a much better place, and just having the model to look at is good.

97
00:07:37,268 --> 00:07:44,636
But we need to do more to interrogate them and extract information to learn the stories we have to tell

98
00:07:45,025 --> 00:07:46,957
and then we also need to share those stories with other people.

99
00:07:47,553 --> 00:07:53,688
So we've been working on a viewer with a few simple tools to help us take the model and say what's going on here.

100
00:07:55,853 --> 00:08:01,918
A very quick at an an 1830s canal bridge and then a bit of a bit of a look at a Clifton suspension bridge.

101
00:08:03,725 --> 00:08:06,140
One slightly sad bridge, and also very faint.

102
00:08:08,568 --> 00:08:15,214
It's just a standard canal bridge. You can see cracks here.

103
00:08:16,493 --> 00:08:21,631
About an hour on site and 2000 photos got us this and gave us this level of detail, where we can see into every crevice

104
00:08:22,051 --> 00:08:26,470
we can see all those lost bricks, and we can see how this bit dropped here.

105
00:08:31,535 --> 00:08:33,336
And we can look around it.

106
00:08:35,413 --> 00:08:36,471
So far, so good.

107
00:08:36,789 --> 00:08:40,350
But we need to understand what's happening. Why is the brickwork here? What's going on?

108
00:08:41,458 --> 00:08:45,127
And what we can do with the viewer is ...

109
00:08:45,326 --> 00:08:54,049
We know there's something funny about the crown. Let's put in a horizontal plane through the point.

110
00:09:01,908 --> 00:09:03,576
And it gives us an imaging contact.

111
00:09:03,859 --> 00:09:05,385
So this is used for the shading engine.

112
00:09:06,086 --> 00:09:11,430
We can see the intersection. We can see that it's lower here. That there's a ...

113
00:09:12,016 --> 00:09:14,679
... at this point.

114
00:09:17,913 --> 00:09:21,872
At this end there's also mould, but not nearly to the same extent ...

115
00:09:23,979 --> 00:09:29,731
... and all of that lets us start to get an understanding of what's going on interactively.

116
00:09:30,089 --> 00:09:33,560
So we can contour this. We can say we've got a mesh, we're going to do a set of contours.

117
00:09:34,121 --> 00:09:36,112
We've got to decide what contours and what spacing.

118
00:09:36,898 --> 00:09:39,325
With this ...

119
00:09:39,524 --> 00:09:43,500
... and play and move it around and see what it is and then go and start producing your contours.

120
00:09:45,626 --> 00:09:48,447
...

121
00:09:48,753 --> 00:09:54,487
This is the Clifton suspension Bridge. You may be familiar with it.

122
00:09:54,939 --> 00:09:57,191
Clifton's over on this side, and Leigh Wood's over here.

123
00:09:57,662 --> 00:10:02,138
This buttress built up about 10 years ago.

124
00:10:02,138 --> 00:10:05,978
Somebody doing some maintenance on the deck lifted a stone up and realised oh there's a big hole here.

125
00:10:07,335 --> 00:10:12,468
There's a shaft that goes down and they looked up and -- from there -- they could see that the shaft goes right down to the depths of the buttress.

126
00:10:14,144 --> 00:10:21,574
And obviously they explored further and discovered that around the shaft there's this whole network of vaults.

127
00:10:22,471 --> 00:10:28,908
So the road comes up over the river, runs along the central vault, and there were these two at the back and off the line.

128
00:10:29,487 --> 00:10:31,972
And nobody had thought, that's a massive abutment ...

129
00:10:35,133 --> 00:10:38,727
But once you know they're there you have to expect them. You have to know you're safe.

130
00:10:39,180 --> 00:10:41,479
Out of sight, out of mind.

131
00:10:42,283 --> 00:10:43,968
Just out of interest.

132
00:10:45,022 --> 00:10:50,720
We've got a laser scanner there. This was early in our photogrammetry exploration. We didn't know if it was going to work in pitch dark.

133
00:10:51,137 --> 00:10:58,634
So we needed the geometric information as well, and we got the laser scan, we got 45GBs

134
00:10:58,878 --> 00:11:00,136
converted that into a textured image

135
00:11:00,468 --> 00:11:02,242
200MB that we can load onto a normal PC.

136
00:11:02,577 --> 00:11:06,859
These models are about 200MB as well, per vault.

137
00:11:09,189 --> 00:11:16,891
This is ... we come in through this tunnel, past this shaft, having gone up another tunnel ...

138
00:11:17,125 --> 00:11:23,398
... coming in from the other level through a ladder in the shaft ...

139
00:11:23,838 --> 00:11:26,805
...at my height you have to remember to put your hand up before you get into it because you can't move your elbow.

140
00:11:33,885 --> 00:11:36,621
We find if we look at the bottom bit and turn it around ...

141
00:11:36,621 --> 00:11:39,678
... we've got these things that throw cast iron ties into the walls ...

142
00:11:39,678 --> 00:11:45,863
... that have been there since this was finished and closed. And they're is packed with timber.

143
00:11:46,748 --> 00:11:50,359
You can see there that they were vertical timbers, with just a bit missing in the middle.

144
00:11:50,679 --> 00:11:54,528
This one was filled with water before the others were discovered.

145
00:11:54,881 --> 00:11:58,145
And it was obviously a very stable level. It's moved up and down by about a foot.

146
00:11:58,601 --> 00:12:02,707
And the timber has rotted where that's happened and there's now coral down there ...

147
00:12:04,232 --> 00:12:09,528
You can look up the top and view along these things which are 10 meters up in pitch dark

148
00:12:09,528 --> 00:12:12,058
and you can see that tie is shining quite brightly.

149
00:12:12,977 --> 00:12:14,923
There's no attention to it.

150
00:12:18,751 --> 00:12:20,871
If we look to ...

151
00:12:21,157 --> 00:12:23,478
... we can see a crack.

152
00:12:24,609 --> 00:12:26,606
We couldn't see that until we looked at the model.

153
00:12:27,105 --> 00:12:28,608
There's no way ...

154
00:12:28,747 --> 00:12:32,636
... that by the time you've wriggled into that space, shining a torch ...

155
00:12:32,965 --> 00:12:34,698
... that you're got to catch features like that ...

156
00:12:34,806 --> 00:12:41,305
... but once you got this you can look at and take your time with about, you can see things that you wouldn't see otherwise.

157
00:12:45,848 --> 00:12:50,378
We can move the plain across here as well.

158
00:12:51,427 --> 00:12:53,230
And ... the plain.

159
00:12:57,309 --> 00:13:01,064
I've set that to just roundabout about springing where the whole starts turning in.

160
00:13:01,845 --> 00:13:07,350
You can turn it over clipping plain and change the clipping direction.

161
00:13:09,950 --> 00:13:13,463
You can go to photographic ... view from below.

162
00:13:16,747 --> 00:13:18,359
And then next to him ...

163
00:13:27,796 --> 00:13:28,494
... colouring.

164
00:13:28,798 --> 00:13:38,190
So if we take a normal vector for every triangle and cover the mesh with that, we can very quickly see changes in matter.

165
00:13:38,754 --> 00:13:47,093
So you can see that although the shape of the bottom planes have curved sides and corners that is carried right onto the bulk of the top.

166
00:13:47,458 --> 00:13:50,380
But we can also see very quickly that there are orange stripes all the way around here

167
00:13:50,380 --> 00:13:55,469
...

168
00:13:55,469 --> 00:14:02,687
So we can start to learn that the walls are built quite easily once we got to the top and built freehand as far as we could.

169
00:14:04,026 --> 00:14:06,367
Because working up there, if we built a center...

170
00:14:06,678 --> 00:14:08,519
... you'd be fighting trying to work out ...

171
00:14:08,764 --> 00:14:12,724
... and you stand at the platform ...

172
00:14:12,917 --> 00:14:14,709
and only at the very top do you put the center in and finish it.

173
00:14:15,056 --> 00:14:19,364
So you can see that it's smooth at the sides. Smooth at the top where the wood would be worked on ...

174
00:14:20,239 --> 00:14:22,780
... there's always roughness in ... masonry.

175
00:14:35,854 --> 00:14:37,329
And there are interesting things like this.

176
00:14:37,936 --> 00:14:42,133
These stones were embedded in the stones. The stones actually slipped forwards as they were building it.

177
00:14:46,786 --> 00:14:48,921
We're going back there next week to do the top level.

178
00:14:49,414 --> 00:14:52,691
So those models are of the bottom, and we're going to back there and do the top one.

179
00:14:53,113 --> 00:14:54,431
I'm a bit nervous about that ...

180
00:14:54,795 --> 00:14:58,890
...

181
00:15:00,849 --> 00:15:06,468
I've been developing a bit of extra kit to try and speed up the process and not just go like ...

182
00:15:09,904 --> 00:15:13,831
So developing an understanding of defects is really hard.

183
00:15:15,170 --> 00:15:20,026
Textured meshes are a lot more useful than point cloud in this respect, and that's not just if you're in the dark.

184
00:15:25,034 --> 00:15:28,890
It's possible to get sub millimeter details for very big structures ...

185
00:15:30,847 --> 00:15:37,920
And being able to take snapshots in time at very high detail gives you an ability to rethink

186
00:15:38,413 --> 00:15:42,472
... whether it's just because you've thought of something and you need to go back and have a look

187
00:15:42,868 --> 00:15:47,155
or because you're looking at it again for a second time.

188
00:15:48,276 --> 00:15:50,082
Thank you.

189
00:15:51,206 --> 00:16:03,035
[APPLAUSE]