@Override
    protected void doDisplayFrustumDebug(int shadowMapIndex) {
        Vector3f[] points2 = points.clone();

        ((Node) viewPort.getScenes().get(0)).attachChild(createFrustum(points, shadowMapIndex));
        ShadowUtil.updateFrustumPoints2(shadowCam, points2);
        ((Node) viewPort.getScenes().get(0)).attachChild(createFrustum(points2, shadowMapIndex));
    }
Sets the light to use to cast shadows

@param light a SpotLight
jme3-core/src/main/java/com/jme3/shadow/SpotLightShadowRenderer.java