@Override
    public void update(){
        super.update();

        // do some animation
        float tpf = timer.getTimePerFrame();
        boxGeom.rotate(tpf * 2, tpf * 4, tpf * 3);

        // don't forget to update the scenes
        boxGeom.updateLogicalState(tpf);
        boxGeom.updateGeometricState();

        // render the viewports
        renderManager.render(tpf, context.isRenderable());
    }
Test a bare-bones application, without SimpleApplication.
jme3-examples/src/main/java/jme3test/app/TestBareBonesApp.java