public static extern simcontrol_error_t simcontrol_set_center_of_eye_mm(IntPtr context, ref simcontrol_point3d_t center_of_eye);
public static extern simcontrol_error_t simcontrol_set_gaze_direction(IntPtr context, ref simcontrol_point3d_t gaze_direction);
public static extern simcontrol_error_t simcontrol_set_gaze_origin_mm(IntPtr context, ref simcontrol_point3d_t gaze_origin_mm);