diff --git a/src/components/three/XRGrabbable.tsx b/src/components/three/XRGrabbable.tsx
index 2c10a61..713db36 100644
--- a/src/components/three/XRGrabbable.tsx
+++ b/src/components/three/XRGrabbable.tsx
@@ -1,7 +1,8 @@
 import { useRef, ReactNode } from 'react';
-import { useFrame } from '@react-three/fiber';
+import { useFrame, useThree } from '@react-three/fiber';
 import * as THREE from 'three';
 import { useControllerGrab, ControllerGrabSnapshot } from '@/hooks/useControllerGrab';
+import { useModelStore } from '@/stores/useModelStore';
 
 interface XRGrabbableProps {
   /** Allow uniform scaling via two-hand grab (distance between hands) */
@@ -42,18 +43,57 @@ const _tmpQuat = new THREE.Quaternion();
  *  • Two-hand grab: midpoint = pivot, axis between hands = rotation,
  *    distance ratio = uniform scale (if allowScale).
  *
- * On release the group keeps its last pose (we don't write to the store —
- * the manual fine-tuning sliders remain available as additional offsets).
+ * Parent re-attach strategy:
+ *  At grab start the group is attached to the Scene root (preserving
+ *  world-transform). At grab end it is re-attached to its original parent
+ *  (typically XRHitTestPlacement), unless `isLocked` is true — in which case
+ *  it stays anchored in world space and the original parent can no longer
+ *  influence its matrix.
  */
 export function XRGrabbable({ allowScale = false, onGrabStart, children }: XRGrabbableProps) {
   const groupRef = useRef<THREE.Group>(null);
   const grab = useControllerGrab();
+  const { scene } = useThree();
 
   const single = useRef<SingleGrabRecord | null>(null);
   const dual = useRef<DualGrabRecord | null>(null);
+  /** Parent the group belonged to before the active grab started. */
+  const originalParent = useRef<THREE.Object3D | null>(null);
   const haloRef = useRef<THREE.Mesh>(null);
+  const lockHaloRef = useRef<THREE.Mesh>(null);
   const everGrabbed = useRef(false);
 
+  const beginGrab = (mode: 'single' | 'dual', hand: 'left' | 'right' | 'dual') => {
+    const group = groupRef.current;
+    if (!group) return;
+    // Reparent to scene root preserving world-transform.
+    if (group.parent && group.parent !== scene) {
+      originalParent.current = group.parent;
+      scene.attach(group);
+      console.log(`[XR][grab] attach→scene (mode=${mode} hand=${hand})`);
+    } else if (!originalParent.current) {
+      originalParent.current = group.parent ?? scene;
+    }
+    if (!everGrabbed.current) { everGrabbed.current = true; onGrabStart?.(); }
+  };
+
+  const endGrab = () => {
+    const group = groupRef.current;
+    if (!group) return;
+    const locked = useModelStore.getState().isLocked;
+    if (locked) {
+      console.log('[XR][grab] release→scene (locked, staying anchored)');
+      return;
+    }
+    const target = originalParent.current;
+    originalParent.current = null;
+    if (target && target !== group.parent) {
+      const name = target === scene ? 'scene' : (target.name || target.type);
+      target.attach(group);
+      console.log(`[XR][grab] release→${name}`);
+    }
+  };
+
   useFrame(() => {
     const group = groupRef.current;
     if (!group) return;
@@ -63,14 +103,20 @@ export function XRGrabbable({ allowScale = false, onGrabStart, children }: XRGra
 
     const lActive = L.isGrabbing && L.hasPose;
     const rActive = R.isGrabbing && R.hasPose;
+    const isLocked = useModelStore.getState().isLocked;
 
     // ─── Halo intensity (visual feedback for analog grip) ────────
     if (haloRef.current) {
-      const maxGrip = Math.max(L.gripValue, R.gripValue);
+      const maxGrip = isLocked ? 0 : Math.max(L.gripValue, R.gripValue);
       const mat = haloRef.current.material as THREE.MeshBasicMaterial;
       mat.opacity = maxGrip * 0.25;
       haloRef.current.visible = maxGrip > 0.05;
     }
+    if (lockHaloRef.current) {
+      const mat = lockHaloRef.current.material as THREE.MeshBasicMaterial;
+      mat.opacity = 0.18;
+      lockHaloRef.current.visible = isLocked;
+    }
 
     // ─── Two-hand mode ───────────────────────────────────────────
     if (lActive && rActive) {
@@ -83,7 +129,9 @@ export function XRGrabbable({ allowScale = false, onGrabStart, children }: XRGra
       axisNow.divideScalar(distNow);
 
       if (!dual.current) {
-        // Capture
+        // Capture — reparent BEFORE snapshotting matrixWorld so subsequent
+        // applyWorldMatrixToLocal math is consistent.
+        beginGrab('dual', 'dual');
         group.updateMatrixWorld();
         dual.current = {
           startGroupWorld: group.matrixWorld.clone(),
@@ -93,7 +141,6 @@ export function XRGrabbable({ allowScale = false, onGrabStart, children }: XRGra
           startScale: group.scale.x,
         };
         single.current = null; // dual takes over
-        if (!everGrabbed.current) { everGrabbed.current = true; onGrabStart?.(); }
         console.log('[XR][grab] ◆ TWO-HAND start');
       }
 
@@ -123,6 +170,7 @@ export function XRGrabbable({ allowScale = false, onGrabStart, children }: XRGra
     } else if (dual.current) {
       console.log('[XR][grab] ◆ TWO-HAND end');
       dual.current = null;
+      if (!lActive && !rActive) endGrab();
     }
 
     // ─── One-hand mode ───────────────────────────────────────────
@@ -130,18 +178,19 @@ export function XRGrabbable({ allowScale = false, onGrabStart, children }: XRGra
     if (activeHand) {
       const slot = activeHand === 'left' ? L : R;
       if (!single.current || single.current.hand !== activeHand) {
+        beginGrab('single', activeHand);
         group.updateMatrixWorld();
         const offset = new THREE.Matrix4()
           .copy(slot.gripWorld).invert()
           .multiply(group.matrixWorld);
         single.current = { hand: activeHand, offset };
-        if (!everGrabbed.current) { everGrabbed.current = true; onGrabStart?.(); }
         console.log(`[XR][grab] ● ONE-HAND start (${activeHand})`);
       }
       _tmpMat.multiplyMatrices(slot.gripWorld, single.current.offset);
       applyWorldMatrixToLocal(group, _tmpMat);
     } else if (single.current) {
       single.current = null;
+      endGrab();
     }
   });
 
@@ -152,6 +201,11 @@ export function XRGrabbable({ allowScale = false, onGrabStart, children }: XRGra
         <sphereGeometry args={[0.5, 16, 12]} />
         <meshBasicMaterial color="#22c55e" transparent opacity={0} depthWrite={false} />
       </mesh>
+      {/* Lock halo — golden, visible while isLocked is true */}
+      <mesh ref={lockHaloRef} visible={false}>
+        <sphereGeometry args={[0.55, 16, 12]} />
+        <meshBasicMaterial color="#f59e0b" transparent opacity={0} depthWrite={false} wireframe />
+      </mesh>
       {children}
     </group>
   );