THREE.SpringCamera.js

THREE.SpringCamera.js

/*
  SpringCamera.js
*/
THREE.SpringCamera = function (_width, _height) {
  /*
  constructor
  */
  var VIEW_ANGLE = 45, ASPECT = _width / _height, NEAR = 0.01, FAR = 10000000;
  this.nextCamPosX =  0;
  this.nextCamPosY =  0;
  this.nextCamPosZ =  0;
  this.curCamPosX =   0;
  this.curCamPosY =   0;
  this.curCamPosZ =   0;
  this.speedX =       0;
  this.speedY =       0;
  this.speedZ =       0;
  this.friction =     0.4;
  this.spring =       0.5;
  this.position.z =   500;
  this.position.x =   0;
  this.position.y =   0;
  this.lookAtPosition = new THREE.Vector3(0, 0, 0);
  this.randPosition =  new THREE.Vector3(0, 0, 0);
  this.init();
  THREE.PerspectiveCamera.call(this, VIEW_ANGLE, ASPECT, NEAR, FAR);
};

THREE.SpringCamera.prototype = new THREE.PerspectiveCamera();

THREE.SpringCamera.prototype.init = function () {
  this.randPosition.x = Math.random() * 12.5 - 6.0;
  this.randPosition.y = Math.random() * 6.5 - 3.0;
  this.randPosition.z = Math.random() * 0.5 - 0.0;
};

THREE.SpringCamera.prototype.update = function (_target) {
  this.position = this.animateCamera();

  switch (_target.mode) {
    case 'FAR':
      this.lookAtPosition = new THREE.Vector3(this.randPosition.x, this.randPosition.y,0);
      break;
    
    case 'NEAR':
        var newPos = new THREE.Vector3(_target.position.x + this.randPosition.x, _target.position.y - this.randPosition.y, _target.position.z + this.randPosition.z);
        this.lookAtPosition = newPos;
        //console.log(_target.name);
      break;

    case 'NEAR_CENTER':
      this.lookAtPosition = _target.position;
      //console.log(_target.name);
      break;

    default:
      break;
  };

  this.lookAt(this.lookAtPosition);
};

THREE.SpringCamera.prototype.next = function (_type, _coordinate) {
  switch (_type) {
    case 'slow':
      this.nextCamPosX = (Math.random() * 200 - 100);
      this.nextCamPosY = (Math.random() * 200 - 250);
      this.nextCamPosZ = Math.random() * 200 + 250;
      this.friction = Math.random() * 0.04 + 0.02;
      this.spring = Math.random() * 0.1 + 0.08;
      break;
    case 'fast':
      this.nextCamPosX = _coordinate.x;
      this.nextCamPosY = _coordinate.y + (Math.random() * 20 - 20);
      this.nextCamPosZ = Math.random() * 20 + 10;
      this.friction = Math.random() * 0.05 + 0.1;
      this.spring = 0.5+ Math.random() * 0.1 + 0.1;
      break;
    case 'fast-far':
      this.nextCamPosX = (Math.random() * 200 - 100);
      this.nextCamPosY = (Math.random() * 200 - 250);
      this.nextCamPosZ = Math.random() * 200 + 300;
      this.friction = Math.random() * 0.02 + 0.07;
      this.spring = 0.5+ Math.random() * 0.1 + 0.05;
      break;
    default:
    break;
  };
};

THREE.SpringCamera.prototype.animateCamera = function () {
  var ax, ay, az;
  ax = (this.nextCamPosX - this.curCamPosX) * this.spring;
  this.speedX += ax;
  this.speedX *= this.friction;
  this.curCamPosX += this.speedX;
  
  ay = (this.nextCamPosY - this.curCamPosY) * this.spring;
  this.speedY += ay;
  this.speedY *= this.friction;
  this.curCamPosY += this.speedY;
  
  az = (this.nextCamPosZ - this.curCamPosZ) * this.spring;
  this.speedZ += az;
  this.speedZ *= this.friction;
  this.curCamPosZ += this.speedZ;

  return new THREE.Vector3( this.curCamPosX, this.curCamPosY, this.curCamPosZ );
};