Hi Yongjin,

First of all, wb_supervisor_get_sf_rotation (documented here) is effectively a function of the supervisor and so it is not usable from an EDU version. This function is used to get the current orientation relatively to the parent node of the given node (here, the GPS solid).

The old GPS was overkilled because it gave information that none of any real device can return (both the position and the exact orientation). As the policy of the new API is to render accessible the non realistic only from the supervisor, we decided to split into several more specialized devices such as the new GPS and the Compass which allows the same abilities than the old GPS. Basically, if you need:

• the position of your robot, use the new GPS device with the wb_gps_get_values function
• the orientation of your robot according to the north, use the Compass device with the wb_compass_get_values function

The orientation given by the old GPS matrix was a little more powerful than the one given by the compass, i.e., getting the orientation along the Compass-North axis is no more possible with the new API unless to use 2 perpendicular compasses. So the euler matrix is no more directly available but must be computed by yourself if needed.

I hope this is clear enough!?
Regards,
Fabien