public Joint readNodeAsBone(int nodeIndex, int jointIndex, int skinIndex, Matrix4f inverseModelBindMatrix)
            throws IOException {
        JointWrapper jointWrapper = fetchFromCache("nodes", nodeIndex, JointWrapper.class);
        if (jointWrapper != null) {
            return jointWrapper.joint;
        }
        JsonObject nodeData = nodes.get(nodeIndex).getAsJsonObject();
        String name = getAsString(nodeData, "name");
        if (name == null) {
            name = "Joint_" + nodeIndex;
        }
        Joint joint = new Joint(name);
        Transform boneTransforms = null;
        boneTransforms = readTransforms(nodeData);
        joint.setLocalTransform(boneTransforms);
        joint.setInverseModelBindMatrix(inverseModelBindMatrix);

        addToCache("nodes", nodeIndex, new JointWrapper(joint, jointIndex, skinIndex), nodes.size());

        return joint;
    }
GLTF 2.0 loader
Created by Nehon on 07/08/2017.
jme3-plugins/src/gltf/java/com/jme3/scene/plugins/gltf/GltfLoader.java