Updated example builds.

examples/js/utils/RoughnessMipmapper.js

@@ -68,6 +68,8 @@
 			material.roughnessMap.repeat.copy( roughnessMap.repeat );
 			material.roughnessMap.center.copy( roughnessMap.center );
 			material.roughnessMap.rotation = roughnessMap.rotation;
+			material.roughnessMap.image = roughnessMap.image; // required for USDZExporter, see #22741
+
 			material.roughnessMap.matrixAutoUpdate = roughnessMap.matrixAutoUpdate;
 			material.roughnessMap.matrix.copy( roughnessMap.matrix );
 			_mipmapMaterial.uniforms.roughnessMap.value = roughnessMap;