@Override
    public void simpleUpdate(float tpf) {
        super.simpleUpdate(tpf);
        sl.setDirection(cam.getDirection());
        sl.setPosition(cam.getLocation());

    }
Uses the terrain's lighting texture with normal maps and lights.

@author bowens
jme3-examples/src/main/java/jme3test/light/TestSpotLightTerrain.java