Index out of range: index should be less than 1175964: 1179937898 [Error on loading .glb file in iOS]

[Mohammad-R-Rashid]

Tested multiple .glb files. Added a modelCache.dart method to try to cache and load. Validated .glb files to make sure it is valid.

Here are some logs:

flutter: Loading Blaster6 model in powerups with improved error handling...
flutter: Loading Blaster6.glb from assets...
flutter: Loaded ByteData: 1175964 bytes
flutter: Created Uint8List: 1175964 bytes
flutter: Written to temp file: /var/mobile/Containers/Data/Application/FA451963-34DF-4EF1-8C60-0DBF291F0EAF/Library/Caches/Blaster6.glb
flutter: Verified written file: 1175964 bytes
flutter: Model preloaded successfully, attempting direct load...
flutter: RangeError with preloaded approach: RangeError (byteOffset): Index out of range: index should be less than 1175964: 1179937898
flutter: Trying direct asset loading with delay...
flutter: RangeError with delayed approach: RangeError (byteOffset): Index out of range: index should be less than 1175964: 1179937898
flutter: Clearing cache and trying again...
flutter: Model cache cleared
flutter: Blaster6 final attempt failed: RangeError (byteOffset): Index out of range: index should be less than 1175964: 1179937898
flutter: All Blaster6 approaches failed. Trying DefaultBlaster as fallback...
flutter: Loading DefaultBlaster.glb from assets...
flutter: Loaded ByteData: 1010104 bytes
flutter: Created Uint8List: 1010104 bytes
flutter: Written to temp file: /var/mobile/Containers/Data/Application/FA451963-34DF-4EF1-8C60-0DBF291F0EAF/Library/Caches/DefaultBlaster.glb
flutter: Verified written file: 1010104 bytes
flutter: RangeError loading DefaultBlaster fallback: RangeError (byteOffset): Index out of range: index should be less than 1010104: 1179937898
flutter: All loading approaches failed, proceeding without 3D model

Render model code:

Future _loadModel() async {
try {
print('Loading DefaultBlaster model with validation...');

  // First, validate the GLB file
  final isValid = await GlbValidator.validateGlbFile('assets/DefaultBlaster.glb');
  if (!isValid) {
    print('DefaultBlaster.glb failed validation, skipping 3D model');
    setState(() {
      model = null;
      isLoading = false;
    });
    return;
  }
  
  final glbInfo = await GlbValidator.getGlbInfo('assets/DefaultBlaster.glb');
  print('DefaultBlaster GLB info: $glbInfo');
  
  // Try multiple approaches to load the model
  Node? loadedModel;
  
  // Approach 1: Try loading with cached model path (preloading)
  try {
    await ModelCacheManager.preloadDefaultBlasterModel();
    print('Model preloaded successfully, attempting direct load...');
    loadedModel = await Node.fromAsset('assets/DefaultBlaster.glb');
    print('Successfully loaded DefaultBlaster model with preloading');
  } on RangeError catch (e) {
    print('RangeError with preloaded approach: $e');
    print('Problematic byte offset: ${e.toString().contains('1179937898') ? 'Known GLB parser bug detected' : 'Unknown offset'}');
    loadedModel = null;
  }
  
  // Approach 2: Try direct loading with delay
  if (loadedModel == null) {
    try {
      print('Trying direct asset loading with delay...');
      await Future.delayed(const Duration(milliseconds: 200));
      loadedModel = await Node.fromAsset('assets/DefaultBlaster.glb');
      print('Successfully loaded DefaultBlaster model with delay');
    } on RangeError catch (e) {
      print('RangeError with delayed approach: $e');
      loadedModel = null;
    }
  }
  
  // Approach 3: Try clearing cache and loading again
  if (loadedModel == null) {
    try {
      print('Clearing cache and trying again...');
      await ModelCacheManager.clearCache();
      await Future.delayed(const Duration(milliseconds: 300));
      loadedModel = await Node.fromAsset('assets/DefaultBlaster.glb');
      print('Successfully loaded DefaultBlaster model after cache clear');
    } catch (e) {
      print('Final attempt failed: $e');
      loadedModel = null;
    }
  }
  
  if (loadedModel != null) {
    setState(() {
      model = loadedModel;
      scene.add(model!);
      isLoading = false;
    });
  } else {
    print('All loading approaches failed - GLB file may be incompatible with flutter_scene package');
    setState(() {
      model = null;
      isLoading = false;
    });
  }

[r2d2Proton]

Getting the same error with the code below

[ERROR:flutter/runtime/dart_vm_initializer.cc(40)] Unhandled Exception: RangeError (byteOffset): Index out of range: index should be less than 4144360: 1179937898

`class ThreeDWidgetState extends State with TickerProviderStateMixin implements PlaygroundWidgetState {

late ThreeDModel? theModel;

late Scene scene;
bool loaded = false;
AnimationClip? idleClip;
AnimationClip? runClip;
AnimationClip? walkClip;

@OverRide
void initState() {
scene = Scene();
final dashModel = Node.fromAsset('assets/models/dash.glb').then((
modelNode,
) {
for (final animation in modelNode.parsedAnimations) {
debugPrint('Animation: ${animation.name}');
}

  scene.add(modelNode);

  idleClip =
      modelNode.createAnimationClip(modelNode.findAnimationByName('Idle')!)
        ..loop = true
        ..play();
  walkClip =
      modelNode.createAnimationClip(modelNode.findAnimationByName('Walk')!)
        ..loop = true
        ..weight = 0
        ..play();
  runClip =
      modelNode.createAnimationClip(modelNode.findAnimationByName('Run')!)
        ..loop = true
        ..weight = 0
        ..play();
});

Future.wait([dashModel]).then((_) {
  debugPrint('Scene loaded.');
  setState(() {
    loaded = true;
  });
});

super.initState();

}

@OverRide
void dispose() {
scene.removeAll();
super.dispose();
}

@OverRide
Widget build(BuildContext context) {
if (!loaded) {
return const Center(child: CircularProgressIndicator());
}
return Stack(
children: [
SizedBox.expand(
child: CustomPaint(
painter: _ScenePainter(scene, widget.elapsedSeconds),
),
),
// Door open slider
if (idleClip != null)
Column(
children: [
const Spacer(),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
for (final clip in [idleClip, walkClip, runClip])
Slider(
value: clip!.weight,
onChanged: (value) {
clip.weight = value;
},
),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Slider(
min: -2,
max: 2,
value: walkClip!.playbackTimeScale,
onChanged: (value) {
idleClip!.playbackTimeScale = value;
walkClip!.playbackTimeScale = value;
runClip!.playbackTimeScale = value;
},
),
],
),
],
),
],
);
}
}

`

[r2d2Proton]

I am debugging this now. . . And I see the line where the numbers get corrupted. I am using dash.glb (4,144,360 bytes). BufferContext bc with offset and length are correct, but after bc.derefObject (dereference object) is called objectOffset has a very large value. I am not sure what is happening, still debugging, but it could be happening on the C++ side of things.

flat_buffers.dart
@override T read(BufferContext bc, int offset) { final objectOffset = bc.derefObject(offset); return createObject(bc, objectOffset); }

My test app is
@override void initState() { super.initState(); scene = Scene(); final dashModel = Node.fromAsset('assets/models/dash.glb').then(( modelNode, ) {