fix: restore viewer state after Quick Look export failure

packages/model-viewer/src/features/ar.ts

@@ -405,7 +405,13 @@ configuration or device capabilities');
 
       this[$arButtonContainer].classList.remove('enabled');
 
-      const objectURL = generateUsdz ? await this.prepareUSDZ() : this.iosSrc!;
+      let objectURL: string;
+      try {
+        objectURL = generateUsdz ? await this.prepareUSDZ() : this.iosSrc!;
+      } catch (error) {
+        this[$arButtonContainer].classList.add('enabled');
+        throw error;
+      }
       const modelUrl = new URL(objectURL, self.location.toString());
 
       if (generateUsdz) {
@@ -487,15 +493,22 @@ configuration or device capabilities');
       }
       exportGroup.updateWorldMatrix(false, true);
 
-      const arraybuffer = await exporter.parseAsync(exportGroup, {
-        maxTextureSize: isNaN(this.arUsdzMaxTextureSize as any) ?
-            Infinity :
-            Math.max(parseInt(this.arUsdzMaxTextureSize), 16),
-      });
-
-      for (const m of models) {
-        exportGroup.remove(m);
-        target.add(m);
+      let arraybuffer: ArrayBuffer;
+      try {
+        arraybuffer = await exporter.parseAsync(exportGroup, {
+          maxTextureSize: isNaN(this.arUsdzMaxTextureSize as any) ?
+              Infinity :
+              Math.max(parseInt(this.arUsdzMaxTextureSize), 16),
+        });
+      } finally {
+        for (const m of models) {
+          exportGroup.remove(m);
+          target.add(m);
+        }
+        if (shadow != null) {
+          shadow.visible = visible;
+        }
+        updateSourceProgress(1);
       }
 
       const blob = new Blob([arraybuffer], {
@@ -504,12 +517,6 @@ configuration or device capabilities');
 
       const url = URL.createObjectURL(blob);
 
-      updateSourceProgress(1);
-
-      if (shadow != null) {
-        shadow.visible = visible;
-      }
-
       return url;
     }
   }

packages/model-viewer/src/test/features/ar-spec.ts

@@ -19,6 +19,7 @@ import {expect} from 'chai';
 
 import {IS_ANDROID, IS_IOS} from '../../constants.js';
 import {$openIOSARQuickLook, $openSceneViewer} from '../../features/ar.js';
+import {$progressTracker, $scene} from '../../model-viewer-base.js';
 import {ModelViewerElement} from '../../model-viewer.js';
 import {waitForEvent} from '../../utilities.js';
 import {assetPath, rafPasses, spy} from '../helpers.js';
@@ -143,6 +144,45 @@ suite('AR', () => {
   });
 
   suite('openQuickLook', () => {
+    test(
+        'restores the viewer after video texture USDZ conversion fails',
+        async () => {
+          element.shadowIntensity = 1;
+          element.src = assetPath('models/cube.gltf');
+          await waitForEvent(element, 'load');
+          const texture =
+              element.createVideoTexture(assetPath('models/lottie-logo.mp4'));
+          element.model!.materials[0]
+              .pbrMetallicRoughness.baseColorTexture.setTexture(texture);
+
+          const scene = (element as any)[$scene];
+          const parent = scene.models[0].parent;
+          const shadowVisible = scene.shadow?.visible;
+          expect(scene.shadow).to.not.be.null;
+          expect(shadowVisible).to.be.true;
+          const button = element.shadowRoot!.querySelector('.ar-button')!;
+          button.classList.add('enabled');
+          const progress = (element as any)[$progressTracker];
+          expect(progress.ongoingActivityCount).to.equal(0);
+
+          let thrown: unknown;
+          try {
+            await (element as any)[$openIOSARQuickLook]();
+          } catch (error) {
+            thrown = error;
+          }
+
+          expect(thrown).to.be.instanceOf(Error);
+          expect((thrown as Error).message)
+              .to.include('No valid image data found');
+          expect([
+            scene.models[0].parent === parent,
+            scene.shadow?.visible === shadowVisible,
+            progress.ongoingActivityCount === 0,
+            button.classList.contains('enabled'),
+          ]).to.deep.equal([true, true, true, true]);
+        });
+
     test('sets hash for fixed scale', () => {
       element.src = 'https://example.com/model.gltf';
       element.iosSrc = 'https://example.com/model.usdz';