copc-loader

COPC (Cloud Optimized Point Cloud) loader for loaders.gl — WASM LAZ decompression in the browser and Node, HTTP-range streaming off any static file host. No server, no ETL, no PDAL.

loaders.gl has no COPC loader today (tracked in visgl/loaders.gl#2911) — this package fills that gap, powered by the wasm-spatial-core engine.

• Verified against real data — decoded chunk-exact against autzen-classified.copc.laz (10.65 M points, 278 chunks, point format 7).
• loaders.gl-compatible — plain loader object, works with parse()/load() from @loaders.gl/core.
• Streaming — loadCOPC(url) fetches the header + chunk table (~KB), then decompresses chunk byte-ranges as they arrive.
• deck.gl-ready — returns POSITION / COLOR_0 attributes.

Install

npm install copc-loader

Parse a whole file (loaders.gl)

import { load } from '@loaders.gl/core';
import { COPCLoader } from 'copc-loader';

const data = await load('https://example.com/scan.copc.laz', COPCLoader, {
  copc: { bbox: [636000, 849000, 400, 637000, 850000, 500] }, // optional subset
});

data.header.vertexCount;      // 10_653_336
data.attributes.POSITION;     // { value: Float32Array, size: 3 }
data.attributes.COLOR_0;      // { value: Uint8Array, size: 3 } (when present)

Stream over HTTP without downloading the whole file

import { loadCOPC } from 'copc-loader';

const controller = new AbortController();
const data = await loadCOPC('https://example.com/scan.copc.laz', {
  bbox: [636000, 849000, 400, 637000, 850000, 500], // post-decode filter
  signal: controller.signal,
  onProgress: ({ chunksDone, chunksTotal, points }) =>
    console.log(`${chunksDone}/${chunksTotal} chunks, ${points} points`),
});

Requires a host that honors Range requests (S3, GitHub Pages, most CDNs and static servers). If the server ignores ranges, the loader falls back to downloading and parsing the full file.

deck.gl

import { Deck } from '@deck.gl/core';
import { PointCloudLayer } from '@deck.gl/layers';
import { loadCOPC } from 'copc-loader';

const { attributes } = await loadCOPC('https://example.com/scan.copc.laz');

new Deck({
  layers: [
    new PointCloudLayer({
      id: 'copc',
      data: { length: attributes.POSITION.value.length / 3, attributes },
      getColor: [255, 255, 255],
      pointSize: 2,
    }),
  ],
});

API

COPCLoader

loaders.gl loader object — id: 'copc', extensions ['copc', 'laz'], test on the LASF magic. Use with any loaders.gl load/parse.

parse(data, options?)

Parse full file bytes. options.copc.bbox restricts output to a [minX, minY, minZ, maxX, maxY, maxZ] subset (hierarchy-aware for COPC files — only intersecting chunks are decompressed).

parseSync(data, options?)

Synchronous variant; call await init() (or any async API) first.

loadCOPC(url, options?)

HTTP-range streaming (see above). Chunks are fetched with bounded concurrency (6) and decompressed as they arrive.

setCore(core)

Inject an already-initialized wasm-spatial-core API instance, if your app already uses the engine.

Notes

• Positions are Float32Array XYZ in the file's CRS (COPC is typically a projected CRS — e.g. UTM meters — check loaderData.copcInfo for scale/offset/bounds).
• Colors are 8-bit RGB derived from the high bytes of the u16 LAS channels.
• Node ≥ 18 (uses global fetch).

License

MIT