code: function(array) {
  				array = array || [];
  				var i = 0;
  				var l = this.vertices.length;
  				for (var j=0;j<l;j++) {
  					var v = this.vertices[j];
  					array[i++] = v.x;
  					array[i++] = v.y;
  					array[i++] = v.z;
  				}
  				return array;
  			}
docs: flatten each vertex once into an array, useful for OpenGL attributes
  @param {Array|Float32Array} [array] optionally pass in an array or typed-array to reuse
  @return {Array|Float32Array}