Platforms with passengers
Lay a platform between two markers. Passengers arrive, wait at the edge, board and alight through the doors. Their colour shows their mood, from green to red.
What goes on the layout
Everything is placed on the real layout in model millimetres and scaled to the prototype, so a person on an H0 platform is 20 mm tall.
Bus terminals
Bays along a bus lane, shelters and stop signs. Buses come on a timetable, or more often when a rail replacement service is running.
Houses and landscape
Buildings with floors and roofs, single trees and forests, fields, water and roads. Tap to place them, drag to move them.
Disruptions and scenarios
Delays, cancellations, closures, signal failures, crowd surges and replacement buses, started by hand or scripted as scenarios for teaching.
Your control system
A small Python bridge forwards train positions over WebSocket. When a real train stops at a platform, the virtual passengers board it.
Your own objects and simulations
Plugins add object types, simulations and disruption types in plain JavaScript modules. The editor builds their settings forms automatically.
How it works
Printed square markers lie flat on the layout. From the camera image alone, without a calibration board, ARail works out where the layout plane is and draws on it.
MarkersArUco or AprilTag codes, 30 mm, anywhere on the layout, any rotation.
Marker mapTheir positions are surveyed from the images and stored with the layout.
Camera poseAll visible markers give one stable view of the plane; the focal length is estimated too.
Virtual layoutPlatforms, bus terminals and scenery from a JSON layout file.
SimulationTrains, buses, passengers and disruptions, in prototype metres and seconds.
Set up your lab
The first four steps take an afternoon. The control system can follow later.
- 1
Print markers
Use the marker sheets and check the 100 mm bar with a ruler. The black square is the marker size.
- 2
Lay them out
One marker at each end of every platform, more across the layout. Wherever the camera looks, one or two should be in view.
- 3
Open the app
Take a photo, record a video or start the live camera. Unknown markers are measured automatically when they are seen next to known ones.
- 4
Build and export
Add platforms, a bus terminal and scenery in the Build panel, then export the layout file and keep it in your fork.
- 5
Connect the control system
Run
arail-bridgenext to it with an adapter for your system. The simulated control system shows the flow without one.
Extend it
No build step, no framework. A plugin is an ES module that registers what it adds; layouts load it by URL.
Guide to plugins · Layout file format · Control-system interface
// plugins/windmill.js: a new object type
export default function (arail) {
class Windmill extends arail.LayoutObject {
static type = "windmill";
static label = "Windmill";
static params = [{
key: "height_m", label: "Height",
type: "number", unit: "m", default: 18,
}];
computeGeometry() {
const c = arail.resolvePoint(this.world.map, this.spec.position);
return c && { center: c };
}
draw(view) {
const [x, y] = this.geometry.center;
const h = view.m(this.spec.height_m); // metres → model mm
view.prism(arail.rectFootprint([x, y], view.m(5), view.m(5)), 0, h,
{ side: "#e8e1d0", top: "#8a5a3c" });
}
}
arail.registry.registerObject(Windmill);
}Departures · project status
as of September 2026| Version | Destination | Status |
|---|---|---|
| 0.1 | Tracking without a calibration boardMarker map survey, focal length estimate, tested on the lab photo | Arrived |
| 0.1 | Platforms, bus terminals, scenery, editorLayout files, plugins, passenger simulation | Arrived |
| 0.1 | Disruptions, scenarios, control-system bridgeSimulated, replayed and TCP JSON feeds | Arrived |
| next | Live sessions in the EBLPhones, webcams and a projector on the real layout | Boarding |
| next | Adapter for the EBL control systemReal train positions instead of the simulator | Scheduled |
| later | Occlusion by real trains, more vehicle typesIdeas and contributions welcome | Scheduled |