Figure 8. Potential at every point; it is highest in the obstacles and lowest at the goal-Design and Implementation of a Fully Autonomous UAV's Navigator Based on Omni-directional Vision System

The numerical potential field path planner is guaranteed to produce a
path even if the start or goal is placed in an obstacle. If there is no possible way to get from the start
to the goal without passing through an obstacle then the path planner will generate a path through
the obstacle, although if there is any alternative then the path will do that instead. For this reason, it
is important to make sure that there is some possible path, although there are ways around this
restriction such as returning an error if the potential at the start point is too high. The path is found
by moving to the neighboring square with the lowest potential, starting at any point in the space and
stopping when the goal is reached.