function Mat4() {
      var elements = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : new Float32Array([1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]);

      _classCallCheck(this, Mat4);

      this.type = "Mat4";
      this.elements = elements;
    }
Here we create a Mat4 class object
   This is a really basic Matrix4 class used for matrix calculations
   Highly based on https://github.com/mrdoob/three.js/blob/dev/src/math/Matrix4.js and http://glmatrix.net/docs/mat4.js.html
     params :
   @elements (Float32Array of length 16): our matrix array. Default to identity matrix.
     returns :
   @this: our Mat4 class object
*