raycaster:pick

pick & place

by Millieyan

HTML

<div id="info">Pick & Place
<p id = 'msg'>
</p>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/107/three.min.js"></script>
<script src="https://threejs.org/examples/js/controls/OrbitControls.js">


</script>
<script src="https://code.jquery.com/jquery-2.1.4.min.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;
var raycaster;
var mouse = new THREE.Vector2();
var pickables = [];
var objects;

init();
animate();

function init() {
  scene = new THREE.Scene();

  camera = new THREE.PerspectiveCamera(50, window.innerWidth / window.innerHeight, 1, 1000);
  camera.position.z = 500;

  var gridXZ = new THREE.GridHelper(240, 24, 'red', 'white');
  scene.add(gridXZ);

  renderer = new THREE.WebGLRenderer();
  renderer.setSize(window.innerWidth, window.innerHeight);
  renderer.setClearColor(0x888888);

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

  document.body.appendChild(renderer.domElement);

  /////////////////////////////////////////////////////////////////////	
	objects = new THREE.Group();
  
  let cube = new THREE.Mesh (new THREE.BoxGeometry(20,20,20), new THREE.MeshNormalMaterial());
  cube.name = 'cube'
  cube.position.set (-50,0,0)
  
	let sphere = new THREE.Mesh (new THREE.SphereGeometry(20,20,20), new THREE.MeshNormalMaterial())
  sphere.name = 'sphere'
  sphere.position.set (50,0,0)

	objects.add (cube, sphere);
  scene.add (objects);
	
  pickables = [ objects ];

  raycaster = new THREE.Raycaster();
  document.addEventListener('mousedown', onDocumentMouseDown, false);
  document.addEventListener('mousemove', onDocumentMouseOver, false);
}

function onDocumentMouseDown(event) {

  mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
  mouse.y = -(event.clientY / window.innerHeight) * 2 + 1;

  // find intersections
  raycaster.setFromCamera(mouse, camera);
  var intersects = raycaster.intersectObjects(pickables, true);
  if (intersects.length > 0) {
		$('#msg').text ('you have picked ' + '"' + intersects[0].object.name + '"')
	} else {
  	$('#msg').text ('nothing picked')
  }

}

function onDocumentMouseOver(event) {
	event.preventDefault();  // may not be necessary
  mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
  mouse.y = -(event.clientY / window.innerHeight) * 2 + 1;

  // find intersections
 ...