Two trains, built from code at runtime

A 3D demo usually hides a file: a model someone built in another tool, then imported and lit. Tom Krcha's point is that there is no such file here. Both trains are generated when the page runs, from TypeScript and Three.js — dimensions, profiles and geometry functions.

That changes what you can do next. An asset can only be swapped; a function can be tuned — a longer carriage, a different shape, an explosion that is the same code run in reverse. The explode-and-reassemble animation is the proof: the train comes apart and returns because it was never a frozen mesh.

And it runs smoothly in a browser. The stack is ordinary. The craft is the decision to generate the object instead of importing it.