Gravity & Grit: Peak District Downhill

A browser-based 3D mountain biking game set in the Peak District, built with Three.js and cannon-es. Ride as Gravity and Grit down real Peak District bridleways — see issue #28 for the naming decision, docs/concept-art-prompts.md for the concept art direction, and docs/style-guide.md for the resulting colour palette and branding rules.

Play it live at joe-heffer.github.io/Peak-District-Downhill, or on itch.io — the game is in active playtesting ahead of a 1.0 release, so feedback on framerate, controls, route feel, and bugs is very welcome (comment on the itch.io page or open an issue).

Controls

Action	Keyboard	Touch
Steer left	← / A	Left zone
Steer right	→ / D	Right zone
Pedal	W / ↑	Pedal button
Brake	↓ / S	Brake button
Jump	Space	Jump button

Pedalling draws down a stamina bar (shown top-left); once it's empty the bike settles into a slower, sustainable pedal rate until stamina recovers.

Other controls: the speaker icon (top-right) mutes/unmutes the music, and ` (backquote) toggles the dev-tools panel (stats, log console, and admin commands).

Getting started

Requires Node.js 20+.

npm install       # install dependencies
npm run dev       # start the dev server
npm run build     # build for production (outputs to dist/)
npm run preview   # preview the production build locally

See docs/itch-io.md for building and publishing the itch.io release (npm run build:itch / npm run package:itch).

Project structure

src/
  main.js                  # entry point, async init, and render/physics loop
  scene/setupScene.js      # Three.js scene, camera, renderer, lighting
  physics/setupWorld.js    # cannon-es physics world + terrain heightfield
  bike/BikeController.js   # bike movement, terrain-aware grounding, camera follow
  input/InputController.js # keyboard and touch input handling
  terrain/                 # loads baked heightmap data, builds the terrain mesh
  routes/                  # loads baked route data, renders the decorative trail line
  style.css
public/data/
  terrain/cutgate.json     # baked heightmap for the Cut Gate descent (generated)
  routes/cutgate.json      # baked route polyline for the Cut Gate descent (generated)
tools/terrain/              # dev-only scripts that (re)generate the files above from
                             # real open geodata — see tools/terrain/README.md

Data & attribution

The terrain and route are modelled on Cut Gate, a real Peak District bridleway descent, using open UK geodata (Environment Agency LIDAR, OpenStreetMap). See ATTRIBUTION.md for licensing details and tools/terrain/README.md for how to (re)generate the data.

Generative AI usage

This project's code was largely written with the help of generative AI — see AI_USAGE.md for details.

Contributing

Contributions are welcome — see CONTRIBUTING.md for the development workflow and commit message conventions.

License

Released under the MIT License.