@Override
    public Spatial detachChildAt(int index) {
        Spatial s = super.detachChildAt(index);
        if (s instanceof Node) {
            unbatchSubGraph(s);
        }
        return s;
    }
Batch this batchNode
every geometry of the sub scene graph of this node will be batched into a single mesh that will be rendered in one call
jme3-core/src/main/java/com/jme3/scene/BatchNode.java