multi viewport

scissorTest is important!

by joe chan

HTML

<div id="info">Multi-Viewports
  <br> press space to toggle Overlapping Viewports
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r78/three.min.js"></script>
<script src="https://threejs.org/examples/js/controls/OrbitControls.js">


</script>
<script src="https://jyunming-chen.github.io/tutsplus/js/KeyboardState.js"></script>

CSS

#info {
  position: absolute;
  top: 0px;
  width: 100%;
  padding: 10px;
  text-align: center;
  color: #ffff00
}

body {
  overflow: hidden;
}

JavaScript

var camera, scene, renderer, controls;
var cameraHUD, sceneHUD;
var keyboard = new KeyboardState();
var overlap = false;

init();
animate();

function initHUD() {

  sceneHUD = new THREE.Scene();
  cameraHUD = new THREE.OrthographicCamera(-10.5, 10.5, 10.5, -10.5, -10, 10);
  cameraHUD.position.z = 5;
  sceneHUD.add(cameraHUD);

  var lineGeometry = new THREE.Geometry();
  lineGeometry.vertices.push(new THREE.Vector3(-10, -10, 0),
    new THREE.Vector3(10, -10, 0),
    new THREE.Vector3(10, 10, 0),
    new THREE.Vector3(-10, 10, 0),
    new THREE.Vector3(-10, -10, 0));
  var line = new THREE.Line(lineGeometry,
    new THREE.LineBasicMaterial({
      color: 0xffffff
    }));
  sceneHUD.add(line);
  var title = new THREE.Mesh(new THREE.PlaneGeometry(6, 3), new THREE.MeshBasicMaterial({
    color: 0xff1234,
    depthTest: false  // important
  }));
  sceneHUD.add(title);

}

function init() {

	 initHUD();
  scene = new THREE.Scene();

  camera = new THREE.PerspectiveCamera(50, window.innerWidth / window.innerHeight, 1, 1000);
  camera.position.z = 5;
  scene.add(camera);

  var geometry = new THREE.BoxGeometry(10, 2, 2);
  var material = new THREE.MeshLambertMaterial();

  var mesh = new THREE.Mesh(geometry, material);
  scene.add(mesh);

  var light = new THREE.PointLight(0xffffff);
  light.position.set(100, 300, 200);
  scene.add(light);

  var gridXZ = new THREE.GridHelper(20, 1, 'red', 'white');
  gridXZ.setColors(new THREE.Color(0xff0000), new THREE.Color(0xffffff));
  scene.add(gridXZ);

  renderer = new THREE.WebGLRenderer();
  renderer.setSize(window.innerWidth, window.innerHeight);
  renderer.setClearColor(0x888800);
  renderer.autoClear = false;

  controls = new THREE.OrbitControls(camera, renderer.domElement);

  document.body.appendChild(renderer.domElement);

}

function animate() {

	controls.update();
  keyboard.update();

  if (keyboard.down('space')) {
    overlap = !overlap;
  }
  requestAnimationFrame(animate);
  render();

}

function render()...