text: J3D.Interactor = function () {
  
      var that = this;
  
      var moveevent = 'mousemove';
  
      // Raw mouse coordinates
      this.pageX = 0;
      this.pageY = 0;
  
      // Normalized mouse coordinates [ 0 to 1 ]
      this.normX = 0;
      this.normY = 0;
  
      // Normalized and centered mouse coodinates [ -1 to 1 ]
      this.centerX = 0;
      this.centerY = 0;
  
      var mousemove = function(e) {
  
          that.pageX = e.pageX;
          that.pageY = e.pageY;
  
          that.normX = e.pageX / window.innerWidth;
          that.normY = e.pageY / window.innerHeight;
  
          that.centerX = that.normX * 2 - 1;
          that.centerY = that.normY * 2 - 1;
      }
  
      this.destroy = function() {
          document.removeEventListener(moveevent, mousemove, null);
      }
  
      document.addEventListener(moveevent, mousemove, null);
  }