protected void updateWorldLightList() {
        if (parent == null) {
            worldLights.update(localLights, null);
            refreshFlags &= ~RF_LIGHTLIST;
        } else {
            assert (parent.refreshFlags & RF_LIGHTLIST) == 0 : "Illegal light list update. Problem spatial name: " + getName();
            worldLights.update(localLights, parent.worldLights);
            refreshFlags &= ~RF_LIGHTLIST;
        }
    }
Should be overridden by Node and Geometry.
jme3-core/src/main/java/com/jme3/scene/Spatial.java