2.1.3. Coordinate Systems

Figure 2.8 shows all markers defined for a body. A RecurDyn model must have one inertial reference frame, which is attached to the ground and automatically created by default. You must not delete the inertial frame.

../_images/image00722.png — Figure 2.8 **Body** and **Coordinate systems**

A body has one body reference frame and one center of mass marker (Center Marker). All markers must be defined relative to the body reference frame. The Origin specifies the origin of a marker in the Marker dialog box. You can specify the orientation of a marker by either 313 Euler Angle or 321 Angle or points along the axes.