public static void main(String[] args) {
        TestSplitScreen app = new TestSplitScreen();
        app.start();
    }
Simple application to test split-screen rendering. Clicking with LMB toggles
between a single camera/viewport (cam) and split screen (leftCam plus
rightCam). See issue #357.
jme3-examples/src/main/java/jme3test/renderer/TestSplitScreen.java