@Override
    public void destroy() {
        if( vrHardware != null ) {
            vrHardware.destroy();
            vrHardware = null;
        }
        DISABLE_VR = true;
        stateManager.cleanup();

        destroyInput();
        if (audioRenderer != null)
            audioRenderer.cleanup();

        timer.reset();
        Runtime.getRuntime().exit(0);
    }
Destroy the application (release all resources).
jme3-vr/src/main/java/com/jme3/app/VRApplication.java