diff --git a/src/components/three/XRControllerMeasure.tsx b/src/components/three/XRControllerMeasure.tsx
new file mode 100644
index 0000000..1702e0d
--- /dev/null
+++ b/src/components/three/XRControllerMeasure.tsx
@@ -0,0 +1,84 @@
+import { useRef } from 'react';
+import { useFrame, useThree } from '@react-three/fiber';
+import * as THREE from 'three';
+import { useModelStore } from '@/stores/useModelStore';
+
+const TRIG_ON = 0.7;
+const TRIG_OFF = 0.3;
+const MAX_RAY = 10; // meters
+
+/**
+ * Right-controller trigger driven measurement for AR.
+ *
+ * When `measureMode` is on and the user pulls the right trigger, casts a ray
+ * forward from the controller (target-ray space). The first mesh hit becomes
+ * a measurement point. Two pulls = one measurement (handled by the store).
+ *
+ * Uses hysteresis so a single trigger pull adds exactly one point.
+ */
+export function XRControllerMeasure() {
+  const { scene, gl } = useThree();
+  const triggered = useRef(false);
+  const raycaster = useRef(new THREE.Raycaster());
+  const tmpOrigin = useRef(new THREE.Vector3());
+  const tmpDir = useRef(new THREE.Vector3());
+  const tmpQuat = useRef(new THREE.Quaternion());
+
+  useFrame((_state, _dt, frame: XRFrame | undefined) => {
+    const measureMode = useModelStore.getState().measureMode;
+    if (!measureMode || !frame) return;
+    const session = frame.session;
+    const refSpace = gl.xr.getReferenceSpace();
+    if (!session || !refSpace) return;
+
+    // Find right controller
+    let right: XRInputSource | null = null;
+    for (const src of session.inputSources) {
+      if (src.handedness === 'right') { right = src; break; }
+    }
+    if (!right) return;
+
+    const gp = right.gamepad;
+    const trigBtn = gp?.buttons?.[0];
+    const trigVal = trigBtn ? (trigBtn.value || (trigBtn.pressed ? 1 : 0)) : 0;
+
+    // Rising edge with hysteresis
+    if (!triggered.current && trigVal > TRIG_ON) {
+      triggered.current = true;
+
+      const raySpace = right.targetRaySpace ?? right.gripSpace;
+      if (!raySpace) return;
+      const pose = frame.getPose(raySpace, refSpace);
+      if (!pose) return;
+
+      const m = new THREE.Matrix4().fromArray(pose.transform.matrix);
+      tmpOrigin.current.setFromMatrixPosition(m);
+      tmpQuat.current.setFromRotationMatrix(m);
+      // Controller aims along -Z in WebXR target-ray convention
+      tmpDir.current.set(0, 0, -1).applyQuaternion(tmpQuat.current).normalize();
+
+      raycaster.current.set(tmpOrigin.current, tmpDir.current);
+      raycaster.current.far = MAX_RAY;
+
+      const hits = raycaster.current.intersectObjects(scene.children, true);
+      const hit = hits.find((h) => {
+        const o = h.object;
+        if (!(o instanceof THREE.Mesh)) return false;
+        if (o.userData.__edgeLine) return false;
+        if (o.geometry instanceof THREE.SphereGeometry) return false;
+        if (o.geometry instanceof THREE.RingGeometry) return false;
+        if (o.geometry instanceof THREE.PlaneGeometry) return false;
+        return true;
+      });
+      if (hit) {
+        useModelStore.getState().addMeasurePoint({
+          x: hit.point.x, y: hit.point.y, z: hit.point.z,
+        });
+      }
+    } else if (triggered.current && trigVal < TRIG_OFF) {
+      triggered.current = false;
+    }
+  });
+
+  return null;
+}