Get the rotation matrix of a placeable geom. In native ODE, the returned values are pointers to internal data structures, so the matrices are valid until any changes are made to the geom. If the geom is attached to a body, the body's rotation matrix will be returned, i.e. the result will be identical to calling dBodyGetRotation. Calling this function on a non-placeable geom results in a runtime error in the debug build of ODE.
the geom's rotation matrix