added doc about pose frames

etc/doxygen/pages/armarpose.dox

@@ -14,6 +14,12 @@ can be called. One needs to give the new frame and the \ref armarx::SharedRobotI
 function.
 - The third level are the LinkedCoordinates (e.g. \ref armarx::LinkedPose "LinkedPose"), which contain all the information needed to do frame transformations.
 
+\section FramedPose-Possible-Frames Frames of coordinates
+The frame of FramedX or LinkedX is technically just a string.
+The possible values are the names of the robot nodes (use \ref RobotAPI-HowTos-RobotViewer "RobotViewer" app of Simox to inspect them).
+For global poses the exists the global constant string variable armarx::GlobalFrame located in the FramedPose.h.
+Use this variable if you specify global poses and an empty Agent-string. Empty frames should be avoided (though, an empty string is mostly considered as the global frame).
+
 \section FramedPose-FramedPositionCreation Creation of new FramedPositions
 To create a new FramedPosition (FramedOrientation, FramedVector and FramedPose work analogously) one needs
 to know the position, the coordinate frame name and the agent name.

source/RobotAPI/libraries/core/FramedPose.h

@@ -54,7 +54,10 @@ namespace armarx
         const VariantTypeId FramedPosition = Variant::addTypeName("::armarx::FramedPositionBase");
         const VariantTypeId FramedOrientation = Variant::addTypeName("::armarx::FramedOrientationBase");
     }
-
+    /**
+     * @ingroup RobotAPI-FramedPose
+     * Variable of the global coordinate system. use this if you are specifying a global pose.
+     * */
     std::string const GlobalFrame = "Global";