//when the frame is rendered, fixed timestep.
        private void OnRenderFrame(object sender, FrameEventArgs e)
        {
            //game logic:

            //render stuff:
            currentEnvironment.OnRenderFrame(masterRenderer);

            masterRenderer.Render(light, camera);

            //finish up rendering:
            display.SwapBuffers();
            mouseWheelDelta = 0;
        }