The default units for length and angles are meters and degrees respectively. Units may be changed using the following global properties:
| Name | Values | Description |
unit_length | "m", "cm", "mm"
| Set the unit length to meters, centimeters or millimeters. |
unit_angle | "degrees", "radians"
| Set the unit angle to degrees or radians. |
Be warned that the length specfication applies to the include files as well, so choose a unit length early and stick to it.