The operator's role is to capture configurations that will be useful for the planner. For example, the operator could help the planner by viewing the workspace representation of the evolving roadmap, and capturing paths of configurations that will enable the planner to connect different roadmap components.
In our implementation, the operator generated sequences of configurations (paths) by attaching the haptic device to the virtual robot and manipulating it in the VE. The system recorded these configurations at regular intervals, and then passed them to the planner.
The configurations generated by the operator could be free (i.e., collision-free configurations of the robot), or approximate (some penetration of the robot into the obstacles is allowed, which can be viewed as `dilating' the robot's free space [11]). In the former case, the planner can directly incorporate the path, while in the latter, it must first transform it into a free path (note that this is not always possible). In both cases, the planner can use the temporal ordering of the collected configurations to speed the connection process.