Point Cloud Viewer (Potree)

Standalone point cloud viewer for COPC, Potree, and EPT data. Renders via Potree, which streams points on-demand based on the camera view. Designed to be served as static files — works locally or on Cloudflare Pages.

Run locally

python3 -m http.server 5504
# open http://localhost:5504

The Potree build artifacts (build/, libs/, laz-perf.wasm) are committed to the repo, so no build step is needed. To re-fetch them from upstream Potree, run ./setup.sh — it overwrites build/ and libs/ with a fresh build.

Supported formats

Auto-detected from the URL:

URL ends with	Format	Notes
.copc.laz	COPC	Cloud Optimized Point Cloud — single self-contained file
metadata.json	Potree 2.0	Converted octree, directory of many files
cloud.js	Potree 1.x	Legacy Potree format
ept.json	EPT	Entwine Point Tile
(anything else)	→ treated as COPC	data.copc.laz is appended as a convention

All four run through the same Potree viewer, so rendering, navigation, and settings are identical.

Loading data

Three ways:

1. Sample buttons — chips at the top of the panel, one per verified public dataset (COPC Autzen, EPT Red Rocks). Adding a Potree 2.0 sample requires a stable public host — none was reliable at port time. Edit the PRESETS array in index.html to add more.
2. URL — paste any URL ending in .copc.laz / metadata.json / cloud.js / ept.json and click Load. Or open the page with ?url=... to auto-load:

   http://localhost:5504/?url=https://example.com/data.copc.laz
   

3. Drag & drop — drag a .copc.laz file from your file manager onto the page. COPC is single-file so this works locally; Potree 2.0 / EPT are multi-file directories and need a URL.

Navigation

• Scroll wheel — zoom toward cursor (Earth Controls switch on after load)
• Double-click — focus on a point
• Left drag — orbit around the focal point
• Right drag — pan
• WASD — fly; hold Shift to go much faster
• R — reset view
• Q / E — down / up

Move speed is auto-scaled to dataset size, so WASD stays responsive on city-sized clouds.

Colors

If the data has RGB attributes, Potree renders them directly. Otherwise the viewer falls back to elevation-based coloring.

CRS support

OpenLayers only knows EPSG:4326 and EPSG:3857 natively. Potree uses proj4 to reproject. This viewer pre-registers 19 Japanese plane-rectangular CRS (EPSG:6669–6687) before Potree looks them up — otherwise an Uncaught EPSG:6676 (or similar) error fires when loading data in those CRS.

To add more CRS, edit the <script> block near the top of index.html that calls proj4.defs(...), and add your projection there before Potree.loadPointCloud runs.

Deploy to Cloudflare Pages

# one-time
npx wrangler login

# deploy current directory as a Pages project
npx wrangler pages deploy .

wrangler.toml already sets pages_build_output_dir = ".", so the project root is uploaded as the static site.

The _headers file:

• forces Content-Type: application/wasm on .wasm files (some CDNs serve them as application/octet-stream, which prevents WebAssembly.instantiateStreaming from initializing laz-perf)
• adds long-lived immutable caching to build/ and libs/.

Total deployed size: ~40 MB across ~390 files — well within Cloudflare Pages' limits (25 MB per file, 20,000 files).

Non-critical errors in the console

• 404 for sources.json — optional Potree 2.0 file. Ignore.
• 404 for attributes.json — same.

The actual point data lives in metadata.json / hierarchy.bin / octree.bin. If those load, the viewer renders.

When nothing shows up

1. Check the URL in DevTools → Network — is Potree getting 200 responses for metadata.json / ept.json / .copc.laz?
2. Check CRS — the File Info panel should show a sensible EPSG. If it's unknown or mismatched, Potree may place the cloud off-screen. Add the CRS to proj4.defs(...).
3. Check the console — Uncaught EPSG:XXXX means a CRS isn't registered.
4. Try double-clicking the map background — fitToScreen is called after load but can fail on edge cases.
5. The on-page status bar now reports HTTP status / CORS errors / parse errors with the detected format label.

References

• Potree: https://github.com/potree/potree
• COPC spec: https://copc.io/
• EPT spec: https://entwine.io/
• Cloudflare Pages: https://developers.cloudflare.com/pages/