All the above data are retrieved by the software system upon user’s request as it is described in section 3.1. Processing is required for the transformation of the path and volumes coordinates into the AR system reference frame, in order for a correct visualization in terms of scale, position and orientation to be achieved. Examples of these cases are shown in Figures 3 and 4. In Figure 3, there is a marker used as reference to superimpose the trajectory of the robot (red line) over the actual image.