@Override
    public void onAction(String name, boolean keyPressed, float tpf) {
        if (name.equals("lmb") && !keyPressed) {
            splitScreen = !splitScreen;
            viewPort.setEnabled(!splitScreen);
            leftView.setEnabled(splitScreen);
            rightView.setEnabled(splitScreen);
        }
    }
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