1 camera 2 displays 1 mirrored.

Working.

HTML

<!--- Using latest THREE.js (r70+) -->
<script src="http://threejs.org/build/three.min.js"></script>
<script src="http://threejs.org/examples/js/controls/OrbitControls.js"></script>

<h1 id="title_A">1 camera, 2 displays (1  mirrored)</h1>


<!-- NB In jsfiddle Frameworks & Extensions select No wrap - in <body> -->

CSS

body {
    background-color: #dddddd;
    margin: 0px;
    overflow: hidden;
}

JavaScript

//... Copies methods presented by Lee Stemkoski and West Langley.

//... Global variables.
var camera1, camera2, scene, renderer, geometry, material, mybox, mybox2;
var renderer_width, renderer_height;
//

init();
animate();

//-------------------------------------------------------------
function init() {

    scene222 = new THREE.Scene();

    camera1 = new THREE.PerspectiveCamera
                (50, window.innerWidth / window.innerHeight, 1, 10000);

    camera1.position.set(0,350,2500);

    //...no effect these two commands
    camera1.projectionMatrix.scale(new THREE.Vector3(1, 1, 1));
    camera1.updateProjectionMatrix();

    scene222.add(camera1);

    //---------------------------------------------------------

    // 2 BOXES
	
    var myboxGeometry = new THREE.CubeGeometry(100, 100, 100);
    var myboxMaterial = new THREE.MeshLambertMaterial({
        color: 0x00aaff,
        side: THREE.DoubleSide
    });


    var mybox2Geometry = new THREE.CubeGeometry(150, 150, 150);
    var mybox2Material = new THREE.MeshNormalMaterial();

    mybox = new THREE.Mesh(myboxGeometry, myboxMaterial);
    mybox.position.set(0, 0, 0);
    scene222.add(mybox);

    mybox2 = new THREE.Mesh(mybox2Geometry, mybox2Material);
    scene222.add(mybox2);
    mybox2.position.set(0, -100, 0);

    // LIGHT
    var light = new THREE.PointLight(0xffffff);
    light.position.set(0, 200, 400);

    //var light = new THREE.AmbientLight(0xffffff);
    scene222.add(light);

    //RENDERER
    //renderer = new THREE.CanvasRenderer();
    renderer = new THREE.WebGLRenderer({
        antialias: true
    });

    renderer_width = window.innerWidth;
    renderer_height = window.innerHeight;
    renderer.setSize(renderer_width, renderer_height);
    renderer.setClearColor(0x444444, 1);
    renderer.autoClear = false;
    document.body.appendChild(renderer.domElement);

    //... Need OrbitControls.js.
    camera1.lookAt(0, 0, 0); //R70
    controls1 = new THREE.OrbitControls(camera1,...