London Dream Railway

Create a dream toy-railway version of London in Three.js: a bright voxel train-table world where little red trains and Tube-like carriages weave through the capital's most famous landmarks. It should feel like the ultimate playroom train set, but with excellent London recognizability.

If you use Three.js, add an import map (before the module script) mapping "three" and "three/addons/" to the same pinned version, and import only via those names. Never reuse identifiers in the same scope - use descriptive variable names.

#### TABLE SETUP

- Let the city sit on a visible playtable or wooden base so the toy-train format is obvious.
- Use elevated tracks, short viaducts, tidy tunnels, and small station platforms.
- The overall layout should be readable from a slightly top-down three-quarter camera.

#### LANDMARKS

- Include Elizabeth Tower / Westminster, Tower Bridge, the London Eye, St Paul's, The Shard, and Battersea.
- Landmarks should be tightly packed around the tracks so trains constantly pass recognizable icons.
- Add small parks and river sections to stop the table feeling too crowded.

#### TRAINS + TRACKS

- Run multiple train loops at once: classic bright-red toy trains, Tube-inspired trains, and maybe a tiny DLR-style shuttle.
- Use branching points or track switches that visibly reroute trains.
- Add a few cutaway tunnel sections so the train movement is easy to follow.

#### STYLE

- Keep everything crisp, bright, and toy-clean.
- Red, blue, yellow, and fresh green should dominate rather than grey realism.
- No dark station lighting, no smoky atmosphere, and no heavy grime.

#### CONTROLS

- Track-switch toggles.
- Train count / speed slider.
- Tunnel cutaway toggle.
- Follow-train camera plus a reset overview.
- Camera presets: full table, bridge crossing, station close-up, tunnel slice.

#### TECHNICAL

- Instanced sleepers, rails, trees, windows, and repeat props.
- Keep train motion smooth and predictable.
- Target >=55 FPS and clamp devicePixelRatio <= 2.