A drivable, walkable 1936 streamlined steam train: loco, tender and 9 furnished cars, a working cab, doors, lights, reclining chairs, procedural sound and smoke, Blueprint API. UE 5.8, Win64.

Your level doesn't need another static train prop. It needs one you can climb aboard. This is a meticulously detailed, complete 1936 streamlined steam passenger train, recreated from period research, and every car is open: walk from the round-end observation lounge through the parlor, lounge, diner and coaches, all the way to the car behind the tender.

End doors slide open as you approach. First-class chairs recline, parlor chairs revolve, the drawing-room door slides open as you reach it, and you can sit down in any seat (X).

Step into the engineer's cab and it drives for real: grab the throttle and reverser, crack the brake valve, pull the whistle cord, and watch the Walschaerts valve gear work in step with the drivers while the gauges settle. Chuffs, rail clicks, the three-chime whistle and the bell are original procedural audio synced to the wheels. A recorded moving-train loop follows your speed and swells in the gangways, and every door plays one of eight recorded open/close sounds.

Stack smoke thickens under load, cylinder cocks spit at the start, and brake sparks fly when you stop hard.

It's built to drop into your project. There's one actor, a Blueprint API with events (speed changed, door opened, station stop, walk car changed), Enhanced Input mappings you can rebind, a data asset to reorder or repeat cars, and support for your own spline track.

Four time-of-day presets take the demo from high noon to glowing night windows. Interiors are culled per car and lights are capped, so the train holds 90+ fps at 1440p on an RTX 4070 (the High preset is recommended for 60 fps on a 3060-class GPU).

## Feature bullets

- 11 vehicles: 4-6-2 streamlined locomotive, tender, baggage, 2x 56-seat coach, 48-seat coach, coach-kitchen, diner, lounge, parlor, observation car

- Full interiors in every passenger car: walkable aisles and gangways, Art Deco wood-panelled bulkheads, upholstered seating, luggage racks, lamps, bar, kitchen

- Drivable: 8-notch throttle, automatic + independent brake with emergency, reverser, auto-drive, speed-based sound and smoke

- Working engineer's cab: drag-to-move levers, moving gauges, firebox door with firelight, whistle and bell cords

- Procedural Walschaerts valve gear, rods and wheels, solved every frame

- Doors: animated side, sliding and automatic end doors, with Blueprint events when they finish

- Lighting: headlight, marker lamps, cabin lights in 4 car groups, 4 time-of-day presets (Day, Golden Hour, Dusk, Night)

- Reclining first-class chairs, revolving parlor chairs, and sit anywhere (X): chairs, coach seats, booths, bar stools and sofas

- 37 sounds: 28 original procedural sounds and 9 recorded effects (a moving-train loop and rotating door open/close sounds), a louder gangway zone, 3 sound classes and a sound mix (master / SFX / ambience volume from Blueprint)

- Niagara stack smoke, idle column, steam, cylinder cocks, safety valve and brake sparks, with procedural flipbooks

- Blueprint API (60+ functions and events), Enhanced Input (3 contexts, 28 actions), consist Data Asset, user spline tracks

- Performance: Nanite meshes, per-car interior culling, 24-light interior cap, ISM instancing, 2K textures

- Demo map with an oval track, station stop, ground and sky

- 6 automation tests and a packaged-build smoke test. Verified in a brand-new blank 5.8 project. Documentation is included (README, integration guide, API reference, troubleshooting)

- Includes a historical 1930s cigarette vending machine prop (unbranded, set dressing only)

## What's included

- The `MercuryStreamliner` code plugin: C++ source (1 runtime module) and all content (meshes, materials, textures, sounds, Niagara systems, input assets, data assets).

- The demo map `/MercuryStreamliner/Maps/Mercury_Demo` (oval track, station stop, generated ground and sky, and an in-editor Read Me).

- Sounds: 28 original procedural sounds by RetroLabs, and 9 recorded effects generated by RetroLabs with ElevenLabs Sound Effects on a paid plan (commercial licence; for use within this product only).

- Documentation: `README.md`, `Docs/Integration.md`, `Docs/API.md`, `Docs/Reference.md`, `Docs/CHANGELOG.md`, `THIRD_PARTY.md`, and the font licences in `Licenses/`.

## What's NOT included

- The showcase environment (curved track, landscape, grass, trees, telegraph poles, dust and the golden-hour cinematic setup) seen in the video and in the exterior screenshots.

Those screenshots are captioned "showcase environment, not included". Only the demo map ships.

- Characters, crew or passengers; skeletal meshes; animations other than the procedural train mechanics.

- Multiplayer / network replication, physics derailment, other platforms (Win64 only) or engine versions (5.8 only).

- DLSS/FSR/XeSS upscalers. Use your own. TSR is the default.

- Source Blender files and the content-generation pipeline.

## Content note

Contains a period cigarette vending machine as unbranded set dressing (no tobacco brands, no smoking).