hw1 prototype

Part 2'

by oKLo

HTML

<div id="info">steer</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r70/three.min.js"></script>
<script src="https://dl.dropboxusercontent.com/u/3587259/Code/Threejs/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 keyboard = new KeyboardState();
var cylinder;

var pos, vel, force;
var angle = 0;

// steer related
var target = new THREE.Vector3 (0,0,-100);
var maxSpeed = 40;
var maxForce = 40;
var targetMesh;


//var power;
var mass=1;
var clock = new THREE.Clock();

init();
animate();

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

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

  // add my cylinder
  var geometry = new THREE.BoxGeometry(15, 2, 5);
  var material = new THREE.MeshNormalMaterial();
  cylinder = new THREE.Mesh(geometry, material);
  scene.add(cylinder);

  var gridXZ = new THREE.GridHelper(100, 10);
  gridXZ.setColors(new THREE.Color(0xff0000), new THREE.Color(0xffffff));
  scene.add(gridXZ);

	targetMesh = new THREE.Mesh (new THREE.CylinderGeometry(3,3,2,20), new THREE.MeshNormalMaterial());
  scene.add (targetMesh);
  
  renderer = new THREE.WebGLRenderer();
  renderer.setSize(window.innerWidth, window.innerHeight);
  renderer.setClearColor(0x888888);

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

	//////////////////////
  pos = new THREE.Vector3();
  vel = new THREE.Vector3(100,0,0);
  force = new THREE.Vector3();
  
  document.body.appendChild(renderer.domElement);
}


function computeForce() {
	// steer
	// force: (target - pos) ... unitize * maxSpeed - vel
  // clamped by maxForce
	var ff = target.clone().sub (pos).setLength (maxSpeed).sub (vel);
  if (ff.length() > maxForce)
  	ff.setLength (maxForce);
  force.copy (ff);
}

function animate() {
	keyboard.update();
  
	computeForce();
	var dt = clock.getDelta();  // delta-time
  vel.add (force.clone().multiplyScalar (dt/mass));
 	pos.add (vel.clone().multiplyScalar (dt));
  
  if (vel.length() > 0.001) {
  	angle = Math.atan2 (-vel.z, vel.x);
  }
  
  // copy to cylinder
  cylinder.position.copy (pos);
  cylinder.rotation.y = angle;
  
 ...