@Override
    public void simpleInitApp() {
        // Two-sided lighting requires single pass.
        renderManager.setPreferredLightMode(TechniqueDef.LightMode.SinglePass);
        renderManager.setSinglePassLightBatchSize(4);
        
        cam.setLocation(new Vector3f(5.936224f, 3.3759952f, -3.3202777f));
        cam.setRotation(new Quaternion(0.16265652f, -0.4811838f, 0.09137692f, 0.8565368f));
        
        Geometry quadGeom = new Geometry("quad", new Quad(1, 1));
        quadGeom.move(1, 0, 0);
        Material mat1 = assetManager.loadMaterial("Textures/BumpMapTest/SimpleBump.j3m");
        
        // Display both front and back faces.
        mat1.getAdditionalRenderState().setFaceCullMode(RenderState.FaceCullMode.Off);
        
        quadGeom.setMaterial(mat1);
        // SimpleBump material requires tangents.
        MikktspaceTangentGenerator.generate(quadGeom);
        rootNode.attachChild(quadGeom);
        
        Geometry teapot = (Geometry) assetManager.loadModel("Models/Teapot/Teapot.obj");
        teapot.move(-1, 0, 0);
        teapot.setLocalScale(2f);
        Material mat2 = new Material(assetManager, "Common/MatDefs/Light/Lighting.j3md");
        mat2.setFloat("Shininess", 25);
        mat2.setBoolean("UseMaterialColors", true);
        mat2.setColor("Ambient",  ColorRGBA.Black);
        mat2.setColor("Diffuse",  ColorRGBA.Gray);
        mat2.setColor("Specular", ColorRGBA.Gray);
        
        // Only display backfaces.
        mat2.getAdditionalRenderState().setFaceCullMode(RenderState.FaceCullMode.Front);
        
        teapot.setMaterial(mat2);
        rootNode.attachChild(teapot);

        lightMdl = new Geometry("Light", new Sphere(10, 10, 0.1f));
        lightMdl.setMaterial(assetManager.loadMaterial("Common/Materials/RedColor.j3m"));
        lightMdl.getMesh().setStatic();
        rootNode.attachChild(lightMdl);

        pl = new PointLight();
        pl.setColor(ColorRGBA.White);
        pl.setRadius(4f);
        rootNode.addLight(pl);
    }
Checks two-sided lighting capability.

@author Kirill Vainer
jme3-examples/src/main/java/jme3test/light/TestTwoSideLighting.java