code: function(faceList) {
  				faceList = faceList || [];
  				var i = 0;
  				var l = this.faces.length;
  				for (var j=0;j<l;j++) {
  					var f = this.faces[j];
  					faceList[i++] = f.a.id;
  					faceList[i++] = f.b.id;
  					faceList[i++] = f.c.id;
  				}
  				return faceList;
  			}
docs: Builds an array of vertex indices of all faces. Each vertex ID
  corresponds to its position in the vertices Array. The
  resulting array will be 3 times the face count.
  please see {@link #getUniqueVerticesAsArray([array])}
  and {@link #getUniqueVertexNormalsAsArray([array])}
  
  @see #getUniqueVerticesAsArray([array])
  @see #getUniqueVertexNormalsAsArray([array])
  
  @param {Array|Unit16Array} [faceList] optionally provide an array or typed-array
  @return array of vertex indices