function() {
      var activeFaces = [];

      for (var i = 0; i < this.faces.length; i++) {
        var face = this.faces[i];

        if (face.mark === Visible) {
          activeFaces.push(face);
        }
      }

      this.faces = activeFaces;

      return this;
    }
function() {
      var activeFaces = [];

      for (var i = 0; i < this.faces.length; i++) {
        var face = this.faces[i];

        if (face.mark === Visible) {
          activeFaces.push(face);
        }
      }

      this.faces = activeFaces;

      return this;
    }
function ( ) { var activeFaces = [ ] ; for ( var i = 0 ; i < this . faces . length ; i ++ ) { var face = this . faces [ i ] ; if ( face . mark === Visible ) { activeFaces . push ( face ) ; } } this . faces = activeFaces ; return this ; }
Removes inactive faces
Removes inactive faces