update Tue 07/14/2026 11:38:16.92

public/js/ar/detect.js

@@ -0,0 +1,22 @@
+/* detect.js — tuned ArUco 4x4 detection.
+ * Phantom-ID fix: reject any marker decoded with hamming distance > 0 (maxHamming: 0).
+ */
+export function createDetector() {
+  return new AR.Detector({ dictionaryName: 'ARUCO_4X4_1000', maxHammingDistance: 0 });
+}
+
+export function detectMarkers(detector, imageData, knownIds) {
+  const markers = detector.detect(imageData);
+  // keep only markers that exist in the scene, with sane geometry
+  return markers.filter(m => knownIds.has(m.id) && quadArea(m.corners) > 100);
+}
+
+export function quadArea(c) {
+  // shoelace
+  let a = 0;
+  for (let i = 0; i < 4; i++) {
+    const p = c[i], q = c[(i + 1) % 4];
+    a += p.x * q.y - q.x * p.y;
+  }
+  return Math.abs(a) / 2;
+}