Interstellar Map

Interactive 3D map of nearby stars using the HYG Database, shown in a Cartesian frame with axes in light-years. Built with Next.js, React Three Fiber, and Three.js. All functions and calculations are based on The Overview Effect's relativistic travel calculator. Star positions are from the HYG catalog, though filtered to only include stars with names. I made this just after watching Project Hail Mary; Can't sleep.

live link

Amaze Amaze Amaze.

Features

• HYG star catalog (filtered CSV) rendered as an instanced point field
• Pan, zoom, and fly through the solar neighborhood
• HUD with search, coordinate readout, and links to data sources
• Optional relativistic travel-time panel (ship time vs Earth time)

Requirements

• Node.js 20+ (22 recommended; matches CI)

Local development

npm install
npm run dev

Open http://localhost:3000. For local dev, leave NEXT_PUBLIC_BASE_PATH unset so the app is served from the site root.

Production build

The app is configured for static export (output: "export"). The production bundle is written to out/.

npm run build

To mimic GitHub Pages (project site under https://<user>.github.io/<repo>/), set the same base path you use on GitHub:

# PowerShell
$env:NEXT_PUBLIC_BASE_PATH="/your-repo-name"; npm run build

# bash
NEXT_PUBLIC_BASE_PATH=/your-repo-name npm run build

Preview the export locally (optional):

npx serve out

Deploy to GitHub Pages

This repo includes a workflow that builds on every push to main or master and publishes with GitHub Actions.

1. Push this repository to GitHub (the repository name becomes the URL path segment, e.g. https://<user>.github.io/interstellarmap/).
2. In the repo on GitHub: Settings → Pages.
3. Under Build and deployment, set Source to GitHub Actions.
4. Run the workflow once (push to main/master, or Actions → Deploy to GitHub Pages → Run workflow).

The workflow sets NEXT_PUBLIC_BASE_PATH to /<repository-name> so routes and the HYG CSV load correctly on a project site.

Custom domain or user/org site at the domain root

If you publish at the root of username.github.io (no repo prefix) or use a custom domain without a subpath, you need an empty base path: change or remove the NEXT_PUBLIC_BASE_PATH line in .github/workflows/deploy-github-pages.yml for your setup, or set it to "" in that job’s env block.

Jekyll and _next

A .nojekyll file in public/ is copied into out/ so GitHub Pages does not ignore Next’s _next assets.

Data

• public/hyg_v42_filtered.csv — star catalog used at runtime
• public/hyg_expl.txt — pointer to HYG documentation

License

Star data is subject to the HYG Database terms; see HYG for attribution and usage.