2-link arm

by 林 羿緯

HTML

<div id="info">demo page</div>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/84/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, mesh, light, controls;
var keyboard = new KeyboardState();
var theta1 = 0;
var theta2 = 0;
var link1, link2;

init();
animate();

function makeLink() {
  var link = new THREE.Object3D();
  var mesh = new THREE.Mesh(new THREE.BoxGeometry(30, 10, 10), new THREE.MeshNormalMaterial());
  link.add(mesh);
  mesh.position.x = 15;
  return link;
}

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

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

  var gridXZ = new THREE.GridHelper(200, 20, 'red', 'white');
  scene.add(gridXZ);

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

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

  document.body.appendChild(renderer.domElement);
  ////////////////////////////////////////////////////////////////////////

	link1 = makeLink(); scene.add (link1)
  link2 = makeLink(); 
  
  link1.rotation.y = theta1;
  link1.add (link2);
  link2.position.x = 30;
  link2.rotation.y = theta2;
}

function animate() {
  controls.update();
  keyboard.update();
  
  if (keyboard.pressed ('Q')) {
  	theta1  += 0.01;
  } else if (keyboard.pressed ('A')) {
    theta1 -= 0.01;
  } else if (keyboard.pressed ('W')) {
    theta2 += 0.01;
  } else if (keyboard.pressed ('S')) {
    theta2 -= 0.01;
  } 


  link1.rotation.y = theta1; 
  link2.rotation.y = theta2;
  
  requestAnimationFrame(animate);
  render();
}

function render() {
  renderer.render(scene, camera);
}

// important to add this 
// in jsfiddle!
window.focus();