Newbury Exhibit v3
Fan-made shared multi-viewer AR experience for a physical LEGO® Hidden Side™ town display (tribute project — not affiliated with the LEGO Group). Multiple phones detect printed "Newbury Crests" (ArUco markers) and see the same server-driven ghosts anchored to real-world positions, each from their own viewpoint.
v3 = v2 with the tracking core replaced. Everything else — playlist engine, residents/tracks, character editor, admin suite, dev error overlay, password- protected final mode, deployment — carries over unchanged.
What changed in v3
The per-marker POS-IT → confidence-weighted fusion pipeline is replaced by a
joint multi-marker board solve (public/js/ar/solve-cv.js, OpenCV.js):
- Every detected crest corner becomes a 3D world point (from
data/scene.jsonanchors, sameanchorWorldMatrixconvention as v2) and onesolvePnPcall recovers the camera pose. No per-marker fusion, no slerp base, no area buckets. - Stability scales with marker spread. Synthetic validation at 0.5px corner noise: ~0.06 cm position / 0.03° rotation error on the full 5-crest board (single-marker POS-IT on the same test: ~2.6 cm / 0.9°).
- The wall crest makes the point set non-coplanar, which removes the POS-IT planar ambiguity (the flip problem) outright whenever it's visible.
- Single visible crest still works: SQPNP/IPPE cold start, then iterative refine warm-started from the previous frame (temporal continuity resolves flips).
- A reprojection-error gate (mean px, shown in the dev HUD) rejects poisoned frames before they reach the 1€ filter.
OpenCV.js (~13 MB WASM) is fetched at Docker build time (pinned
@techstark/opencv-js@4.12.0-release.1) and lazy-loaded on the client after
Start. If it fails to load, the app falls back to the v2 engine automatically.
Dual engines (on-table A/B)
The complete v2 pipeline (detect.js → pose.js → fuse.js) ships alongside
the new one until the board solve is confirmed on the real table.
Dev HUD overlay tap zones (thirds):
| zone | opencv engine | posit engine |
|---|---|---|
| top | switch engine | switch engine |
| middle | axis mode (std/ymirror) |
rotation mode (fr/…) |
| bottom | — | camera correction (none/…) |
Engine choice persists in localStorage (nbx.engine). Optional per-device
horizontal FOV override: localStorage nbx.hfovDeg (default 60, both engines).
axis ymirror exists as on-device insurance: if the world appears mirrored /
camera under the table in opencv mode, tap the middle third once.
First-time load (in place of v2)
git clone https://gitea.hideawaygaming.com.au/jessikitty/newbury-exhibit-v3.git ~/newbury-exhibit-v3
cd ~/newbury-exhibit-v3 && bash load-v3.sh
load-v3.sh imports the unchanged v2 base files into this repo (one commit,
pushed — set GITEA_TOKEN=… if the machine has no git credentials), copies
.env and any locally-dropped public/models from the v2 checkout, stops the
v2 container, and brings v3 up on the same host port, container name, and
exhibit-live volume — live scene/playlist/character state carries over.
- Future deploys:
cd ~/newbury-exhibit-v3 && bash deploy.sh(same as v2). - Rollback any time:
cd ~/newbury-exhibit && docker compose up -d --build.
Conventions (unchanged from v2)
- World units cm; origin front-left table corner; +X right, +Z back, +Y up.
- Marker print sizes stay in mm (
sizeMM); single mm→cm conversion at the solver boundary. data/*.jsonare committed seeds;data/live/(volume) is runtime state.maxHammingDistance: 0— hamming-1 detections are 100% phantoms here.
LEGO® and Hidden Side™ are trademarks of the LEGO Group, which does not sponsor, authorise or endorse this project.