diff --git a/src/components/three/ModelViewer.tsx b/src/components/three/ModelViewer.tsx
index a46f032..47f0dbe 100644
--- a/src/components/three/ModelViewer.tsx
+++ b/src/components/three/ModelViewer.tsx
@@ -352,15 +352,70 @@ function MeasurementLabel({ position, text, variant, fixed = false }: { position
   );
 }
 
-/** Renders all measurements, snap point, and hover info */
+/** Renders a single measurement's geometry + label.
+ *  Coordinates are interpreted in whichever frame the component is mounted in. */
+function MeasurementGraphic({ m }: { m: import('@/stores/useModelStore').Measurement }) {
+  const a: [number, number, number] = [m.pointA.x, m.pointA.y, m.pointA.z];
+  const b: [number, number, number] = [m.pointB.x, m.pointB.y, m.pointB.z];
+  const mid: [number, number, number] = [
+    (a[0] + b[0]) / 2,
+    (a[1] + b[1]) / 2,
+    (a[2] + b[2]) / 2,
+  ];
+
+  if (m.kind === 'hole') {
+    return (
+      <group>
+        <PointMarker position={a} color="#f59e0b" />
+        <MeasurementLabel position={a} text={m.label ?? `Ø ${m.distanceMM.toFixed(1)}`} variant="accent" />
+      </group>
+    );
+  }
+
+  if (m.kind === 'edge') {
+    return (
+      <group>
+        <PointMarker position={a} color="#22c55e" />
+        <PointMarker position={b} color="#22c55e" />
+        <Line points={[a, b]} color="#22c55e" lineWidth={2} depthTest={false} />
+        <MeasurementLabel position={mid} text={m.label ?? `${m.distanceMM.toFixed(1)} mm`} variant="success" />
+      </group>
+    );
+  }
+
+  return (
+    <group>
+      <PointMarker position={a} color="#22c55e" />
+      <PointMarker position={b} color="#22c55e" />
+      <Line points={[a, b]} color="#22c55e" lineWidth={2} depthTest={false} />
+      <MeasurementLabel position={mid} text={`${m.distanceMM.toFixed(1)} mm`} variant="success" />
+    </group>
+  );
+}
+
+/** Renders measurements attached to a given model, in that model's local frame.
+ *  Mounted inside GLBModel so they follow the model when it is repositioned. */
+function ModelMeasurements({ modelId }: { modelId: string }) {
+  const measurements = useModelStore((s) => s.measurements);
+  const attached = measurements.filter((m) => m.modelId === modelId);
+  if (attached.length === 0) return null;
+  return (
+    <>
+      {attached.map((m) => (
+        <MeasurementGraphic key={m.id} m={m} />
+      ))}
+    </>
+  );
+}
+
+/** Renders snap indicator, hover tooltip, pending point and any *legacy*
+ *  world-frame measurements that aren't attached to a specific model. */
 function MeasurementOverlay() {
   const measurements = useModelStore((s) => s.measurements);
   const measurePoints = useModelStore((s) => s.measurePoints);
   const snapPoint = useModelStore((s) => s.snapPoint);
   const hoverInfo = useModelStore((s) => s.hoverInfo);
   const measureMode = useModelStore((s) => s.measureMode);
-  const scaleRatio = useModelStore((s) => s.scaleRatio);
-  const factor = scaleRatio?.factor ?? 1;
 
   return (
     <>
@@ -381,55 +436,15 @@ function MeasurementOverlay() {
         />
       )}
 
-      {/* Pending first point */}
+      {/* Pending first point (always in world coords) */}
       {measurePoints.length === 1 && (
         <PointMarker position={[measurePoints[0].x, measurePoints[0].y, measurePoints[0].z]} color="#e8a838" />
       )}
 
-      {/* Completed measurements */}
-      {measurements.map((m) => {
-        const a: [number, number, number] = [m.pointA.x, m.pointA.y, m.pointA.z];
-        const b: [number, number, number] = [m.pointB.x, m.pointB.y, m.pointB.z];
-        const mid: [number, number, number] = [
-          (a[0] + b[0]) / 2,
-          (a[1] + b[1]) / 2,
-          (a[2] + b[2]) / 2,
-        ];
-
-        if (m.kind === 'hole') {
-          return (
-            <group key={m.id}>
-              <PointMarker position={a} color="#f59e0b" />
-              <MeasurementLabel position={a} text={m.label ?? `Ø ${m.distanceMM.toFixed(1)}`} variant="accent" />
-            </group>
-          );
-        }
-
-        if (m.kind === 'edge') {
-          return (
-            <group key={m.id}>
-              <PointMarker position={a} color="#22c55e" />
-              <PointMarker position={b} color="#22c55e" />
-              <Line points={[a, b]} color="#22c55e" lineWidth={2} depthTest={false} />
-              <MeasurementLabel position={mid} text={m.label ?? `${m.distanceMM.toFixed(1)} mm`} variant="success" />
-            </group>
-          );
-        }
-
-        return (
-          <group key={m.id}>
-            <PointMarker position={a} color="#22c55e" />
-            <PointMarker position={b} color="#22c55e" />
-            <Line
-              points={[a, b]}
-              color="#22c55e"
-              lineWidth={2}
-              depthTest={false}
-            />
-            <MeasurementLabel position={mid} text={`${m.distanceMM.toFixed(1)} mm`} variant="success" />
-          </group>
-        );
-      })}
+      {/* Legacy world-frame measurements (no modelId) */}
+      {measurements.filter((m) => !m.modelId).map((m) => (
+        <MeasurementGraphic key={m.id} m={m} />
+      ))}
     </>
   );
 }