Enable ImageBitmap for external textures in Model

Author: lilleyse

CHANGES.md

@@ -20,6 +20,7 @@
 - Fixed broken image URL in the KML Sandcastle. [#9579](https://github.com/CesiumGS/cesium/pull/9579)
 - Fixed an error where the `positionToEyeEC` and `tangentToEyeMatrix` properties for custom materials were not set in `GlobeFS`. [#9597](https://github.com/CesiumGS/cesium/pull/9597)
 - Fixed misleading documentation in `Matrix4.inverse` and `Matrix4.inverseTransformation` that used "affine transformation" instead of "rotation and translation" specifically. [#9608](https://github.com/CesiumGS/cesium/pull/9608)
+- Fixed a regression where external images in glTF models were not being loaded with `preferImageBitmap`, which caused them to decode on the main thread and cause frame rate stuttering.
 
 ##### Deprecated :hourglass_flowing_sand:
 

Source/Scene/GltfImageLoader.js

@@ -275,7 +275,9 @@ function loadImageFromUri(resource) {
     return loadCRN(resource);
   }
   // Resolves to an ImageBitmap or Image
-  return resource.fetchImage();
+  return resource.fetchImage({
+    preferImageBitmap: true,
+  });
 }
 
 /**

Source/Scene/Model.js

@@ -2032,7 +2032,9 @@ function parseTextures(model, context, supportsWebP) {
       } else if (crnRegex.test(uri)) {
         promise = loadCRN(imageResource);
       } else {
-        promise = imageResource.fetchImage();
+        promise = imageResource.fetchImage({
+          preferImageBitmap: true,
+        });
       }
       promise
         .then(imageLoad(model, id, imageId))