@Override
    public void simpleInitApp() {
        Box b = new Box(1, 1, 1); // create cube shape
        Geometry geom = new Geometry("Box", b);  // create cube geometry from the shape
        Material mat = new Material(assetManager,
          "Common/MatDefs/Misc/Unshaded.j3md");  // create a simple material
        mat.setColor("Color", ColorRGBA.Blue);   // set color of material to blue
        geom.setMaterial(mat);                   // set the cube's material
        rootNode.attachChild(geom);              // make the cube appear in the scene
    }
Sample 1 - how to get started with the most simple JME 3 application.
Display a blue 3D cube and view from all sides by
moving the mouse and pressing the WASD keys.
jme3-examples/src/main/java/jme3test/helloworld/HelloJME3.java