Jekyll2026-09-01T06:56:45+00:00https://zanderlowry.com/feed.xmlAlexander LowrySoftware engineer. Notes on code, models and miniatures, and things worth memorizing.Alexander LowryWASM for Offline-First Collaboration2026-09-01T00:00:00+00:002026-09-01T00:00:00+00:00https://zanderlowry.com/posts/wasm-offline-collaborationMy customers on Thank You, Five! kept losing WiFi in the middle of rehearsals, and the software has realtime collaboration. Keeping both offline capability and realtime collaboration is a contradiction.

Realtime collaboration requires a constant connection. Spotty WiFi means queuing actions up and sending them later. I am building stage management software for theatre teams, and theatres, with old buildings, thick walls, half of them working out of a basement, are close to the worst case for this. Attenuation is bad through cinderblocks.

WASM fit the problem perfectly. You can compile the same code for your server’s architecture and the VM that runs in the browser, and it works identically. I wrote the reconciliation algorithm in Rust and compiled it for the client, so every client runs an exact copy of the server’s algorithm. Actions get a temporary timestamp and edits apply locally. When a client that dropped off comes back, the server rewinds time and runs reconciliation against all client actions. The divergent clocks stop mattering, so long as two people aren’t editing the exact same characters. The server reconciles, sends the truth back to every client, and each one re-applies the same history plus whatever it has done since. Server and client settle on the full truth through a short conversation, and the document comes out perfectly intact.

To my own surprise, it rescued a document of mine before it ever rescued a customer’s. I was dogfooding. I’d volunteered to take minutes at a theatre board meeting, when a double-escaping bug started dropping escaped escape sequences into the text I was typing. My undo made it worse, because undo applies deltas in reverse by character index and the indices were corrupt. But the history had every delta from the beginning, so I reconstructed the whole document by replaying them in order. The design I built for bad WiFi turned out to be the thing that made a bad bug recoverable. The bug has since been fixed, but I’m glad I went the way I did.

It’s fast, too. WASM runs slower than native, but considerably faster than JavaScript. It has picked up real speedups over the last few Chrome releases, and new proposals for streaming the bytecode and better dynamic linking are quickly eliminating its downsides. The era of WASM is genuinely cool.

]]>Alexander LowryThe Idea2024-10-17T00:00:00+00:002024-10-17T00:00:00+00:00https://zanderlowry.com/posts/drinkrig-the-idea Before I could do much, I had to learn how to do anything at all. I had no experience in model making or mini painting before, so I started with some industrial pieces. Of course, I went straight to Thingiverse to look. A crate by Printed-Toys and an electrical box by NYC3D work very well for this purpose. I also thought a drinkrig could use a crane, so I found this one by Mikesrailway. It's an old rail crane, which I think the inhabitants of a drinkrig might cannibalize for moving things around.

Two printed crates side by side; the upper one bare white plastic with a wash, the lower one primed first and noticeably smoother.
The top is white PLA with only a weathering wash. The bottom is a primer then a weathering wash. The primer helps hide the layer lines from printing.
Several test pieces painted in different bright colors over a gray base, all reading as muddy.
Trying different colors. Bright colors on the gray base doesn't work well. It ends up very muddy.
A finished crate with convincing weathered, rusted paint.
Final look process gives what I think is a good look: First, print in white. You can go darker but you can't go lighter. Then two layers of a thicker primer, a layer of color, then a wash for weathering.
The test pieces photographed under flat diffuse LED panels standing in for daylight.
Testing daytime light. All I have is diffuse LED panels, so this obviously isn't very convincing. Perhaps I just need to take these outside. Color never works the way you expect when you first shine those lights on it.
The same test pieces lit blue to simulate night.
Testing night lighting. Not sure if I love this, but blue light might work better than darkness for night.

And with that, I had my proof of concept. Of course, after your first success, your confidence shoots up tremendously, so I went on to work on the main truss.

]]>Alexander LowryThe Drinkrig2024-10-17T00:00:00+00:002024-10-17T00:00:00+00:00https://zanderlowry.com/posts/drinkrig The finished drinkrig model: a tall lattice tower carrying stacked platforms, sheds and a greenhouse, standing in daylight above a bed of clouds.
The completed drinkrig.

Recently, one of my friends started an Apocalypse World game where he homebrewed the setting. Gideon is an imaginative and vivid storyteller, so I was instantly enthralled by his verbal pictures of this world he had imagined:

My friends, the world you know is drowned. Generations ago, the machines of the old world smothered the land in dense, sulfurous, acutely toxic clouds. These rusty yellow clouds came to be colloquially known as the sulfur sea. Humanity was forced to seek safety above the sea. Generations later, descendants of the wealthy survivors of the smothering assumed all walks of life, and the name of the Earth was lost. The Earth is dead, gentlemen. Long live the Ochrelands.

Some inhabitants of today's brutal Ochrelands found solace above the sea on stilted drinkrigs, like the old world's oil rigs, that stand high above the clouds and support large, unmoving populations. Many of them also pump water up from below the sulfur sea, hence their name and their relative security.

Gideon, on the setting of his Apocalypse World game.

In just two paragraphs, so much sprang to mind for me. I had bought 3D printers to make game miniatures, and I hadn't yet. So I got to work.

Process Posts

  1. The Idea
  2. 3D Printing Girders

Photos

The whole drinkrig at night, its windows and lamps glowing warm against dark clouds.
The lower deck of the drinkrig at night, lit from within.
A tiny H0-scale Coca-Cola vending machine tucked into a back corner of the rig, spotlit by a gooseneck lamp.
When I found this H0-scale coke machine, I knew exactly what I had to do with it. It's a detail tucked away in a back layer, but it still gets the hero treatment with the gooseneck lamp.
A small shed on the rig at night, with a miniature notice sign posted beside the door.
The tiny notice sign here is really funny to me for some reason.
The upper platforms of the drinkrig at night.
The upper platforms of the drinkrig in daylight.
The shed on the rig in daylight, showing weathered paint and rust.
Inside the drinkrig's greenhouse: rows of tiny plants over a textured dirt floor.
A second view into the greenhouse, showing the dirt texture and planting beds.
I love the dirt on the floor in here. The plants are one touch that made the greenhouse become clearer, and gave it complexity and color, but the texture of the dirt really sells it.
]]>Alexander Lowry3D Printing Girders2024-10-16T00:00:00+00:002024-10-16T00:00:00+00:00https://zanderlowry.com/posts/drinkrig-girders After learning the basics from my first 3D-printed components, I got to work on the drinkrig itself. The core part of this project was obviously going to be the central structure that supported a drink rig. I had never drafted anything before, and I knew I wasn't going to be able to create something with any complexity quickly. So I set out to Thingiverse to see if I could find what I was looking for.

I found this model by user torleif, which is an OpenSCAD file that allowed me to make the truss to my exact size.

CAD drawing of a square lattice truss tower.

I then cut it in quarters diagonally, and presto, it was easy to print!

Four flat truss sides printed as separate pieces, lying on the print bed.
As you can see, the plate side looks much nicer than the top side. Instead of spending time ironing, I can just put the worse side on the inside.

Then I can paint the pieces and glue them together.

The assembled truss painted gray with brown rust streaks running down it.
A base gray plus a brownish wash on the top sides makes a wonderful rust. If you look closely, you can see the weird texture on the inside. But it's more of a background than anything.

Fantastic! Next, for a sense of scale, I thought I'd add a ladder up the side. This wasn't very hard to draft, even with my low skills. I'm working at H0 scale, which is 1:87. That makes the ladder very small indeed!

A printed ladder only a few millimeters wide, thinner than a finger.

I then found a fire escape, and, after some really fiddly gluing and painting, started to arrange the fire escape on the truss.

The tiny ladder and fire escape crudely arranged against the girder, with mold-a-rama figures visible behind.
You might recognize a few mold-a-rama objects in the back. 3D printing from an earlier age.

The final product looks really nice!

The finished truss with fire escape and ladder attached, rising out of a sea of fluffy clouds.

And with the truss done, it's time to move on to the upper (more complex) parts of this build.

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