public void notifyReshape(int w, int h) {
        for (ViewPort vp : preViewPorts) {
            if (vp.getOutputFrameBuffer() == null) {
                Camera cam = vp.getCamera();
                cam.resize(w, h, true);
            }
            notifyReshape(vp, w, h);
        }
        for (ViewPort vp : viewPorts) {
            if (vp.getOutputFrameBuffer() == null) {
                Camera cam = vp.getCamera();
                cam.resize(w, h, true);
            }
            notifyReshape(vp, w, h);
        }
        for (ViewPort vp : postViewPorts) {
            if (vp.getOutputFrameBuffer() == null) {
                Camera cam = vp.getCamera();
                cam.resize(w, h, true);
            }
            notifyReshape(vp, w, h);
        }
    }
Internal use only.
Updates the resolution of all on-screen cameras to match
the given width and height.

@param w the new width (in pixels)
@param h the new height (in pixels)
jme3-core/src/main/java/com/jme3/renderer/RenderManager.java