private void loadConnections(FbxElement element) {
        for(FbxElement e : element.children) {
            if(e.id.equals("C")) {
                String type = (String) e.properties.get(0);
                long objId, refId;
                FbxObject obj, ref;
                switch(type) {
                case "OO":
                    objId = (Long) e.properties.get(1);
                    refId = (Long) e.properties.get(2);
                    obj = allObjects.get(objId);
                    ref = allObjects.get(refId);
                    if(ref != null) {
                        ref.link(obj);
                    } else if(refId == 0) {
                        obj.linkToZero();
                    }
                    break;
                case "OP":
                    objId = (Long) e.properties.get(1);
                    refId = (Long) e.properties.get(2);
                    String propName = (String) e.properties.get(3);
                    obj = allObjects.get(objId);
                    ref = allObjects.get(refId);
                    if(ref != null)
                        ref.link(obj, propName);
                    break;
                }
            }
        }
    }
FBX file format loader
<p> Loads scene meshes, materials, textures, skeleton and skeletal animation.
Multiple animations can be defined with {@link AnimationList} passing into {@link SceneKey}
or loaded from different animation layer.</p>
jme3-plugins/src/fbx/java/com/jme3/scene/plugins/fbx/SceneLoader.java