Australian Contour Tiles

Quick start (MapLibre GL JS)

The archive is served with CORS enabled and HTTP range support, so MapLibre can read tiles directly from it using the pmtiles protocol — no tile server involved:

<!-- maplibre-gl v5 is the last major with a script-tag (UMD) build; v6+ is ESM-only -->
<script src="https://cdn.jsdelivr.net/npm/maplibre-gl@5.24.0/dist/maplibre-gl.js"></script>
<script src="https://cdn.jsdelivr.net/npm/pmtiles@4.5.0/dist/pmtiles.js"></script>
<script>
  const protocol = new pmtiles.Protocol();
  maplibregl.addProtocol("pmtiles", protocol.tile);

  const map = new maplibregl.Map({ container: "map", /* your base style */ });
  map.on("load", () => {
    map.addSource("contours", {
      type: "vector",
      url: "pmtiles://ARCHIVE_URL",
      attribution: "Contours © Geoscience Australia, CC-BY 4.0",
    });
    // is_index arrives as the STRING "0"/"1", so wrap it in to-number —
    // ["==", ["get","is_index"], 1] silently matches nothing.
    map.addLayer({
      id: "contour-regular", type: "line",
      source: "contours", "source-layer": "contour",
      filter: ["!=", ["to-number", ["get", "is_index"]], 1],
      paint: { "line-color": "rgb(179,134,89)", "line-width": 0.5, "line-opacity": 0.5 },
    });
    map.addLayer({
      id: "contour-index", type: "line",
      source: "contours", "source-layer": "contour",
      filter: ["==", ["to-number", ["get", "is_index"]], 1],
      paint: { "line-color": "rgb(166,116,66)", "line-width": 1.1, "line-opacity": 0.65 },
    });
  });
</script>

The same file works anywhere PMTiles is supported: MapLibre (web and native), QGIS 3.32+, Felt, and the pmtiles CLI.

Plain z/x/y endpoint

If your client can't speak PMTiles, a conventional tile endpoint fronts the same archive, edge-cached on Cloudflare's network:

https://tiles.contour-map-tiles.net/contours/{z}/{x}/{y}.pbf

Empty tiles (ocean, or outside Australia) answer 204 rather than 404. Prefer the pmtiles:// URL where you can — it's served straight from storage with no request limits in front of it.

Download or extract a region

Grab the whole continent (11.9 GB):

curl -O ARCHIVE_URL

Or pull just your area of interest with the pmtiles CLI — this range-reads only the tiles inside your bounding box, so it's fast and small (Tasmania is ~350 MB, a single national park usually a few MB):

# bbox = minLon,minLat,maxLon,maxLat  (this one is Tasmania)
pmtiles extract ARCHIVE_URL \
  tasmania-contours.pmtiles \
  --bbox=144.5,-43.9,148.5,-39.5

Need MBTiles for an offline mobile app? pmtiles convert does the conversion.

What's in the tiles

The DEM is warped to 2× its native density with cubic-spline resampling before contouring, which traces smooth curves between the 30 m elevation samples instead of polygonal lines along the pixel lattice. Australia is processed as 2°×2° cells with buffered edges, so contours join seamlessly across cell boundaries.

How it was built

This tileset is a by-product of building offline topo maps for a hiking-trail guide app. The full pipeline — chunked, resumable, one continent on one machine — is open source in that repo: scripts/build-contours-australia.ts. A write-up of the build (and the failures along the way) is coming soon.

Licence & attribution

Elevation data © Commonwealth of Australia (Geoscience Australia), licensed under CC-BY 4.0. The derived contour tiles are likewise CC-BY 4.0 — free for any use, including commercial, with attribution.

Suggested map attribution:

Contours © Geoscience Australia, CC-BY 4.0

The tiles are provided as-is, with no uptime guarantee — for production use, please pmtiles extract your region and host it yourself (any static bucket works).