Not A Big Deal, part 1: Photogrammetry

I’ve taught myself something new: here is a very tiny Deal Castle, made entirely by me!

This is the very first print, with some design flaws that I’ve now resolved. But more on that later.

Back in the Before-Times, a beloved uncle who lives in Walmer gave me this handmade wooden model of Deal Castle as a wedding gift, which is really how this all started.

I love the Device Forts – they’re a bit before my usual historical period, but a striking, wonderful missing link between classic medieval castles and proper trace italienne gunpowder forts. I’ve always been quite keen on making tiny models, but unfortunately dyspraxia makes me far too clumsy for the sort of fine detail work  So, inspired by various goings-on, including a friend on a Discord server having fun with his new 3d printer, I wondered if I could instead try my hand at crafting 3d models on a computer and leave the difficult “producing this in real life” part to machines. This coincided with me hearing about a technique called photogrammetry.

Photogrammetry in its essence is “using a number of pictures of something to work out how it looks in its entirety”, but digital photogrammetry is a recent and very interesting technique of feeding a lot of separate digital photos of something into software which assembles a 3d model of it (complete with textures.) Rather than a LIDAR-based scan, the physical shape of the object is determined just from the photos. It’s been used for various things, including making scenery in computer games, for archaeology, for budget production of 3d models in the heritage sector, and just for fun – I really recommend David Fletcher’s twitter for some examples of what can be done.
My very first attempt!
So I started (having had a good long google session to determine that this wouldn’t be terribly breaching the relevant netiquette) with a lovely drone video of Deal Castle on Youtube by Oszibusz. (Actually, I had to download the video, then run it through another piece of software to cut it unto hundreds of individual photos, but that’s by the by.) Putting this through Regard3d, a free and reasonably sophisticated piece of, didn’t take too long and immediately gave an encouraging if rather mushy, lumpy result.

Genuinely no idea how this happened.
I started looking into other packages, but realised that my computer – while fine for games – had the wrong kind of graphics card for other photogrammetry tools (most of which are also quite expensive). And I was ultimately convinced, from various photogrammetry examples I was finding (including this astonishingly good Walmer Castle, just up the road) that this technique just wasn’t going to do what I want it to (produce good enough models to 3d print).

So, it was time to teach myself some CAD instead…

hail the æolian orchestrelle

I had known about the Kew Bridge Steam Museum, with its gigantic beam engines, ever since I was big enough to want to ride on a steam train, but had never heard of the Musical Museum just a little way west of it until, after our jaunt around Richmond Park, Tom and Bex took me there. It’s quite easy to miss, tucked away in a plasticky new West London housing development, and incredibly good. For this is a museum of musical machines: a collection, spanning the last century and a half, of dozens of different devices for recording and replaying noises which, magnificently, keeps them all in working order

I hope you’re hailing it.

With a small group of mixed ages, we were shown around the collection by a wonderful old gent called Roy, who explained and briefly played each one. I’d grown up with Leonard de Vries’ incredible Victorian Inventions book on one shelf and The Best of Que Sera on the next, so was already vaguely familiar with wax phonograph cylinders and the like, but some of these were brand new to me: a very early metal disc (adjusting quite how old the gramophone record-laserdisc-CD-DVD-hard drive concept), various bonkers machines with actual chopped-off bits of violin and trumpet inside them, and increasingly sophisticated ways of getting music out of a piano without a pianist.

“Polyphon” metal disc, invented in 1870.
Now you can have a string quartet without needing any friends!
The excellent Roy.

An early pianola: it’s a big set of mechanical fingers which play a piano for you, which was quickly superseded by teaching pianos to play themselves. But this can be applied to a modern keyboard to play ridiculous electronic parps.

 

Why you should hail it.

Piano-player was superseded by self-playing piano, and rolls which mechanistically struck notes on cue replaced by ways of actually recording a specific pianist, demonstrated by this utterly ghostly recording of Shostakovich (I… think?)

 

 

 

 

 

A side room had a number of slightly more modern devices – things I don’t recognise with MOOG written on them, a rotary speaker I more or less understand, a gloriously tacky early theremin, ancient batteries and a home hydro-generator for when houses had water but not electricity plumbed. Fancy! It also had this incredibly louche looking saxophonist.

And finally, after we had an evening coffee and parted, I found this hidden on my coat. I have no idea how on earth Tom made it.

The Musical Museum is obviously closed at the moment cos of the whole Pandemic Thing, but I look forward to taking certain family members back there, and highly recommend it.

 

 

 

PS: All this reminds me strangely of another machine that makes noise: Jolly Jack at the Hull museum. Enjoy!

a walk in the woods

This trip actually took place on 23 Feb 2020, but I’m posting it in 2021.

Richmond Park, designated as a hunting preserve by Charles I but far, far older, is the largest and easternmost of London’s royal parks. It’s big enough and wild enough that you can imagine yourself in the open country, rather than with London bustling all around – until you glimpse the glint of a skyscrapers on the horizon, or the jets coming into Heathrow break the silence. The trains of southwest London are abominable on a Sunday, with any number of lines just not working like they ought to, but I managed to get to Richmond station and, a happy surprise, was almost immediately hailed from a coffee shop by an old boss. London sometimes feels like a very small place.

I met Tom and Bex and we proceeded to the north side of the park, finding a map covered in wonderfully macabre old names – Gibbet Hill, Killcat Corner, any number of Copses better read with an extra R. It was a dark, windy day, with a stiff westerly swishing in the long yellow grass and the knobby grey trees, and hurrying dark clouds off towards the city centre. We came to a bunker-esque structure, plausibly an air raid shelter but small, overengineered and a bit in the middle of nowhere. A mystery.

Cars are allowed to use a couple of roads through the park , but limited to a comical 20mph, which sadly hasn’t reduced their numbers. On either side of the slowly rumbling SUVs, grazing with supreme unconcern, were herds of the park’s two deer species: red to the north, fallow to the south. For photos, we improvised an optical zoom by holding phone cameras to binoculars, although they didn’t seem at all frightened of us. Both sets had grown antlers: short, reserved-looking horns on the red deer, much bigger, more antlery-looking antlers on the dapplebacked fallow.

As we advanced into the ancient (and less-ancient, some trees tagged with Victorian plaques) forest, Tom discussed some theories in a book he’d read recently* about how trees communicate with one another (on most of which I’m not wholly convinced, but not wholly unconvinced either.) And, almost as a side note, how almost everything seems to hurt or kill trees, seen on a long enough timescale, and that they show symptoms which can be reasonably interpreted as suffering. This, in combination with a late-winter deadness, gave a strong, unexpected sense of being surrounded by death, an uncomfortable graveyard air that had never occurred to me before (and I didn’t help by bringing up the lignin theory I’d recently learned about, with its strange imagery of immense piles of dead trees, unable to decay.**) But then again, death is interesting: here, a bark-stripped body striated with wood grain, streamlining around knots and branches like a diagram depicting laminar flow; there a huge, half-decayed shipwreck of dead wood, riddled with beetle-holes. A few green shoots were coming in around the spiky chestnut litter; noisy green parakeets and small, glossy jackdaws were everywhere, and we talked about colonies of ants who formed in acorns, or twigs.

We mused on different theories of the “natural” state of the forest, the immensely old and wide anthropogenic geography; on the effects of clearnces and brushwood collection, and the more recent Victorian habits of cutting off low branches and removing dead trees out of a sense of tidiness. Looking at one grove of oaks, maybe a century old, I noticed that only those at the edge of the group had grown peripheral branches.

At a cold, grey, two-stage lake, strong winds blew little zephyrs of ripples away from us and a pair of swans held their heads low to look menacing. Someone, or several someones over some time, had been building shelters by stacking branches against hollow trees. We found one very nearly big enough for the three of us, and hid in it the rain suddenly swept in, drinking tea from a thermos and eating some excellent homemade banana cake.

And it was a grand day out.

* The Hidden Life of Trees by Peter Wohlleben. From summaries it seems like some genuinely interesting concepts with some big side orders of anthropomorphisation and pseudoscience, but I really want to read it now.