Accessing Skeleton/Armature in Three.js from GLB Files

When importing a rigged model from Blender to Three.js using GLTFLoader, the skeleton/armature is actually included in the file but might not be immediately visible in the scene graph. This is because the skeleton is typically attached to a SkinnedMesh rather than appearing as a separate object.

How to Access the Skeleton

When you load a GLB file with GLTFLoader, the skeleton is associated with the SkinnedMesh. You can access it like this:

JAVASCRIPTCopied
const loader = new GLTFLoader();

loader.load('your-model.glb', (gltf) => {
  const scene = gltf.scene;
  
  // Find the SkinnedMesh in the loaded model
  scene.traverse((object) => {
    if (object.isSkinnedMesh) {
      console.log('Found SkinnedMesh:', object);
      
      // Access the skeleton
      const skeleton = object.skeleton;
      console.log('Skeleton:', skeleton);
      
      // Access bones
      console.log('Bones:', skeleton.bones);
    }
  });
  
  // Add the model to your scene
  yourScene.add(scene);
});

Visualizing the Skeleton

If you want to visualize the skeleton/bones in your scene, you can use the SkeletonHelper:

JAVASCRIPTCopied
const loader = new GLTFLoader();

loader.load('your-model.glb', (gltf) => {
  const scene = gltf.scene;
  
  // Find the SkinnedMesh
  scene.traverse((object) => {
    if (object.isSkinnedMesh) {
      // Create a skeleton helper to visualize the bones
      const skeletonHelper = new THREE.SkeletonHelper(object);
      skeletonHelper.visible = true;
      
      // Add the helper to your scene
      yourScene.add(skeletonHelper);
    }
  });
  
  yourScene.add(scene);
});

Common Issues

1. Make sure your mesh is properly parented to the armature in Blender
2. Ensure the armature has proper bone weights assigned to the mesh
3. Check that you're exporting with the correct settings (which you've already done)
4. Verify that the model is actually a SkinnedMesh when loaded in Three.js

The skeleton data is there, but it's accessed through the SkinnedMesh object rather than appearing as a separate entity in the scene graph.