public void restartRenderer()
        {
            displayTimer = new UpdateStatsTimer();

            if (rtRenderer != null)
            {
                rtRenderer.JoinRenderThread();
                rtRenderer.dispose();
                rtRenderer = null;
            }

            try
            {
                rtRenderer = new RayTracer(frame, width, height, targetFPS, maxBounces, forceCPU);
            }
            catch (Exception e)
            {
                FPS.Content = e.ToString();
                Trace.WriteLine(e.ToString());
            }
        }