public object ThreadPoolCallback(Object threadContext)
        {
            Debug.WriteLine("Loading scene... ");

            Stopwatch stopwatch = Stopwatch.StartNew();
            Raytracer raytracer = new Raytracer();
            raytracer.prepareScene(m_sceneFileName);
            stopwatch.Stop();

            Debug.WriteLine("Finished: loading scene [" + stopwatch.Elapsed.ToString()+"]");

            Debug.WriteLine("Start: rendering");

            stopwatch = Stopwatch.StartNew();
            raytracer.startRaytracing(m_display);

            stopwatch.Stop();

            Debug.WriteLine("Finished: rendering ["+ stopwatch.Elapsed.ToString()+"]");

            return null;
        }