don't rotate images by default.

render.py

                         help="Volume of output file in percent. Defaults to 100%%.")
     parser.add_argument("-i", "--interpolate", dest="interpolate", default=10, type=int,
                         help="Steps on interpolated paths. Defaults to 10.")
-    parser.add_argument("-r", "--rotate", dest="angle_d", default=10, type=int,
-                        help="angle to rotate Defaults to 10.")
+    parser.add_argument("-r", "--rotate", dest="angle_d", default=0.0, type=float,
+                        help="Angle to rotate image, in degrees. Defaults to 0 deg.")
 
     args = parser.parse_args()
     print(args)