fixed USDZ rotation (#4753)

Author: elalish

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

@@ -425,7 +425,7 @@ configuration or device capabilities');
 
       await this[$triggerLoad]();
 
-      const {model, shadow} = this[$scene];
+      const {model, shadow, target} = this[$scene];
       if (model == null) {
         return '';
       }
@@ -441,7 +441,10 @@ configuration or device capabilities');
       updateSourceProgress(0.2);
 
       const exporter = new USDZExporter();
+      target.remove(model);
+      model.updateWorldMatrix(false, true);
       const arraybuffer = await exporter.parse(model);
+      target.add(model);
       const blob = new Blob([arraybuffer], {
         type: 'model/vnd.usdz+zip',
       });

packages/modelviewer.dev/examples/augmentedreality/index.html

@@ -382,7 +382,7 @@ <h4></h4>
           </div>
           <example-snippet stamp-to="customButton" highlight-as="html">
             <template>
-<model-viewer ar camera-controls touch-action="pan-y" src="../../shared-assets/models/Astronaut.glb" alt="A 3D model of an astronaut">
+<model-viewer ar camera-controls touch-action="pan-y" auto-rotate src="../../shared-assets/models/Astronaut.glb" alt="A 3D model of an astronaut">
   <button slot="ar-button" style="background-color: white; border-radius: 4px; border: none; position: absolute; top: 16px; right: 16px; ">
       👋 Activate AR
   </button>