📙 #085 - The Sentinel, adventures in animation

Mark Moxon, as of four days ago has finished his incredibly deep dive into the 1986 BBC Micro game The Sentinel - and to call it an “incredibly deep dive” is to undersell it an almost unforgivable amount - it starts with…

This site contains reconstructed source code for The Sentinel, Geoff Crammond’s classic proto-VR game for the BBC Micro, with every single line documented and (for the most part) explained.

…and then just gets more awesome from there.

I’ve always had a soft spot for this game, especially the procedurally generated landscapes, all 10,000 of them. So little system space to work with on those machines, and it not only managed to create landscapes that looked like art to 14 year old me, but also cleverly got harder the higher up the levels you went, while remaining playable/solvable.

I’d always wanted to recreate them so I could go revisit and explore without all the mild anxiety of playing the game. But a very early — and as it turns out incorrect — assumption about how the levels worked always put me off digging in further.

But with a four day Easter holiday weekend, a sense of adventure, slightly too much confidence, very rusty memory of the 6502 assembly language, and armed with both Mark’s detailed overview of the landscape generation algorithm: thesentinel.bbcelite.com/deep_dives/generating_the_landscape.html & source code: thesentinel.bbcelite.com/source/main/subroutine/generatelandscape.html I wrangled created the landscape inside my normal pen plotter tools.

The Sentinel colour palette mode.

Pen Plotter shaded mode.

The nice thing about old school 3d polygons that start at the back and draw over one another as you get closer to the “camera”, is that it’s fairly easy to convert it all into flat SVG polygons and lines that you can then (after running the nextdraw CLI hidden line removal command) send to the plotter.

Silver on Black landscape

🎞️ 🎞️ 🎞️ 🎞️ 🎞️

# GET ANIMATED

I’ve been seeing a few pen plotted animations recently, the one from the start of last week’s newsletter, and the sequencefest show from a couple of newsletters before that, and I figured it was about time I had a go.

With all the pieces in place by the end of the holiday - picking landscapes from 1-9999, moving the “camera” to set up a shot, automating a looping fly-through or orbit; it didn’t take much to add in the ability to make it automatically export out X number of frame as SVG files from a loop, and scale them down to tile onto sheets of paper.

Then, shoot loads of photos.

To end up with an animation like this…

Here’s another “cell sheet” with 48 frames in 16:9 ratio…

…which I successfully turned into 48 slightly out of focus shots, so yeah, that’s going to have to wait until next week now, ffs.

Meanwhile, the ArtFrame is busy spending 14h 27m drawing the second half of a 64 frame animation on (for the paper nerds) an A1 sheet of delightful Bockingfords hotpressed 300gsm watercolour paper.

Next week I’m going to cut them up into postcards, number them (or number them, then cut them up, honestly I’m not sure the best way around to do that), take photos for the animation and then send them off to the Patreon members.

So if you want one (or often three, tbh) jump on that now, or not, because…

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🛒 🛒 🛒 🛒 🛒

# ALMOST SHOP, RISO

As I’m sure any pen plotter artist who maintains a shop (here’s a few) will tell you, setting it up, keeping it maintained, adding things (paying fees), is a pain in the ass. Consequently I’m totally dragging my feet on this.

But I’m slowly getting my shit together, and things like the above postcards will end up in the shop if there’s any left once the post office has had the chance to fuck-up the very simple job of taking letters from A to B (unless B happens to be either the USA, Switzerland or Germany, in which case it’s apparently not a simple job at all 🤷‍♂️).

I’ve learnt to always plot/keep more than necessary incase I need to resend any; but now I have several from previous months sitting in a draw. Hopefully the tutorial-video 👉 patreon 👉 shop pipeline will flow nicely with about a month or two grace between each part.

Completely separate but kinda not, I’m still in the process of setting up the Riso Studio (a location across town from my own studio) as a place artists can drop in and try their hand at Riso printing, zine making and general print shenanigans. I helped someone Riso print part of their dissertation the other day, and that was very satisfying.

As part of all that I’m writing various tools to help with colour separation, generating previews of roughly what the Riso print will look like (turns out fluorescent pink doesn’t translate to screen RGB particularly well), and preparing files to print. Basically everything I can to make my, the studio and the artists’ lives as easy as possible.

Riso print in Bright Red and Medium Blue

There’s a good chance there’ll be a limited-ish edition of, ummmmm, 10,000 landscapes in pen plotted, riso printed or tradition printed formats, so if you happen to have a favourite landscape number that isn’t 0000 or 0001 then you may be in luck.

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# THE END

Shop stuff will of course go here when it happens, I’m still faffing around with Dark Forest OS, and still not ready to give an opinion.

Nightmare; I’m going to be starting a Riso substack newsletter soon, which’ll be in the alternating Thursday slot that this one isn’t. Thankfully co-riso-studio-owner Clare and I have agreed that rather than write it together, which would never work, we’re going to take it in turns.

I suspect mine will be the more sweary version. On the one hand, oh fuck I’m committing to writing even more, on the other it’s only 12-13 times a year, which doesn’t sound so bad when I put it like that.

Double Nightmare; I’m doing more and more stuff in the “Culture, Archives and Museums Vertical” — and as you can tell — I’m already practicing for the inevitable LinkedIn-ing I’m going to have to do for that.

Perhaps I’m somehow naturally drawn to threes, as I now appear to have three roles; Drawing Machine Artist, Riso Studio Owner, and Digital Legacy Death Doula (no, your children do no want to inherit 63,427 (excluding duplicates) photos spread across several services).

If someone said “Wow Dan, you’ve done a really good job of diversifying income streams, like wot those $97 how to be an influencer courses say you should do” - I would say; yes - diversified, no to the income part 😬

I’ll catch you in the next newsletter on Thursday 30th Apr, maybe the Riso newsletter sometimes after that, and perhaps the are-you-a-GLAMP-or-LOCKSS-organisation at some point in the future.

Love you all
Dan
🧡