In this video the white spaceship is attracted to the goal (transparent green) and repulsed from the obstacle (black sphere) using 3 control points, drawn as red, green, and blue cubes. Several starting orientations are used, and the resulting trajectories are depicted with colored pyramids. (Aaron T. Becker ECE 550, 2007)
![](https://i.ytimg.com/vi/NTPsBgv7PVE/mqdefault.jpg)